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Abstract:

A continuous manufacturing method and system for liquid-crystal display
elements which enhances accuracy, increases speed and improves in yield
in the continuous production of liquid crystal elements. The continuous
method and system performs steps of, defining a plurality of defective
and normal-polarizing-sheet slitting positions on a continuous web of
optical film, based on positions of defects existing in the optical film,
and applying only normal polarizing sheets to a liquid-crystal panel. The
polarizing sheet includes the defective and normal-polarizing-sheet
slitting positions recorded as encoded information which is used to
determine whether the polarizing sheet defined between slit lines
sequentially formed in the continuous web, is a normal polarizing sheet,
peeling the normal polarizing sheet from the carrier film and applying
the normal polarizing sheet to the liquid-crystal panel.

Claims:

1. A continuous manufacturing system for liquid-crystal display elements
adapted to use a continuous web of optical film comprising a polarizer
film having an adhesive layer thereon a carrier film and information
encoded thereon, the encoded information indicating positions for
slitting the continuous web of optical film based on positions of defects
present in the continuous web of optical film, the system comprising; a
feeding unit for continuously feeding the continuous web of optical film
to a lamination station; a measuring device for measuring a feed distance
of the continuous web and calculating a feed-length measurement data
based on the feed distance; a reading unit for reading the encoded
information recorded on the continuous web; a slitting unit for forming a
plurality of slit-lines in the continuous web by slitting the continuous
web from a surface opposite to the carrier film to a depth reaching a
surface of the carrier film adjacent to the adhesive layer, along the
slitting positions, based on the encoded information and the feed-length
measurement data, when the slitting position defined in the continuous
web thereon comes to a slitting station; a control unit for determining
whether the polarizing sheets being formed between an adjacent pair of
the slit-lines sequentially formed in the continuous web is a defective
polarizing sheet having one or more defects or a normal polarizing sheet
having no defect; a peeling unit for peeling the polarizing sheet
determined to be the normal polarizing sheet, among the polarizing sheets
formed between an adjacent pair of the slit-lines sequentially formed in
the continuous web of optical film, from the carrier film and
transporting the peeled polarizing sheets to the lamination station; and
a lamination unit for sequentially transporting liquid-crystal display
elements to the lamination station in synchronization with the
transportation of the normal polarizing sheets to the lamination station
and applying the polarizing sheets to respective ones of the
liquid-crystal display element in a sequential manner.

2. The system in accordance with claim 1, further comprising a
defective-polarizing-sheet removal unit for preventing the polarizing
sheets determined to be defective polarizing sheets among the polarizing
sheets being formed between respective pairs of the slit-lines
sequentially formed in the continuous web of optical film, from being
applied to the liquid-crystal display element.

3. The system in accordance with claim 2, wherein the lamination unit for
applying the normal polarizing sheet to a liquid-crystal display element
further includes; a pair of lamination rollers provided at the lamination
station for movement toward and away from each other, and an adjustment
unit for detecting the position of the normal polarizing sheet
transported in synchronization with a conveyance of the liquid-crystal
display element to the lamination station and for adjusting the position
of the normal polarizing sheet with respect to the liquid-crystal display
element at the lamination station; the adjustment unit being adapted to
perform operations of; adjusting alignment between a leading edge of the
transported normal polarizing sheet and a leading edge of the
liquid-crystal display element conveyed in synchronization with the
transportation of the normal polarizing sheet toward a nip defined
between the pair of lamination rollers located in spaced-apart relation;
thereafter closing the lamination rollers; and laminating the normal
polarizing sheet to the liquid-crystal display element by the lamination
rollers.

4. The system in accordance with claim 1, further comprising a slitting
position verifying unit for verifying if the position of a slit-line
actually formed in the continuous web of optical film in the direction
transverse to the feed direction coincides with the slitting position at
which the slit-line is to be formed.

5. The system in accordance with claim 4, wherein the slitting position
verifying unit is adapted to adjust the position at which the slit-line
is to be formed in the continuous web of optical film by controlling the
slitting unit based on a deviation in the feed direction between the
position of the slit-line actually formed in the continuous web, and the
slitting position at which the slit-line is to be formed in the direction
transverse to the feed direction of the continuous web of optical film.

6. The system in accordance with claim 2, wherein the
defective-polarizing-sheet removal unit comprises a dummy-film drive
mechanism having a dummy-film feed path to which the defective polarizing
sheets formed in the continuous web of optical film are to be attached
and a shifting mechanism for shifting the continuous web of optical film
toward the dummy-film feed path, the shifting mechanism being moved when
the defective polarizing sheet arrives at the removal station to have the
continuous web shifted into contact with the dummy-film feed path so as
to peel the defective polarizing sheet from the continuous web and attach
the defective polarizing sheet to the dummy-film feed path.

7. The system in accordance with claim 2, wherein the
defective-polarizing-sheet removal unit comprises a dummy-film drive
mechanism having a dummy film feed path for attaching the defective
polarizing sheet thereto and a movable roller constituting a part of a
dummy-film feed path, said movable roller being moved, when the defective
polarizing sheet arrives at a nip of the lamination rollers provided in
said lamination station and spaced apart from each other, to replace one
of the lamination rollers with the movable roller so that the movable
roller is cooperated with the other of the lamination rollers, to peel
the defective polarizing sheet from the continuous web, and attach the
defective polarizing sheet to the dummy-film feed path.

8. The system in accordance with claim 1, further comprising a
liquid-crystal display element transportation unit comprising; a storing
magazine for storing a plurality of liquid-crystal display elements; a
take-out unit for sequentially taking out the liquid-crystal display
elements from the storing magazine; and a liquid-crystal orientation
controlling unit for controlling the orientation of a liquid-crystal
display element conveyed to the lamination station in synchronization
with the normal polarizing sheet formed in the continuous web of optical
film at the time of being transported sequentially to the lamination
station.

9. The system in accordance with claim 8 wherein the liquid-crystal
orientation controlling unit further comprising; a sheet leading edge
detecting unit for detecting position of the leading edge of the normal
polarizing sheet, the leading edge extending in a direction transverse to
the feed direction of the continuous web of optical film; a
liquid-crystal display element leading edge detecting unit for detecting
position of the leading edge of the liquid-crystal display element, the
leading edge extending in a direction transverse to the feed direction of
the liquid-crystal display element; and an orientation controlling unit
for controlling orientation of the liquid-crystal display element, in
accordance with information relating to the position of the leading edge
of the normal polarizing sheets and the leading edge of the
liquid-crystal display element provided by the sheet leading edge
detecting unit and the liquid-crystal display element leading edge
detecting unit.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a Divisional Application of U.S. patent
application Ser. No. 12/790,282, filed May 28, 2010, which claims
priority from, PCT application numbers PCT/JP2008/000987 and
PCT/JP2009/001440, respectively filed on Apr. 15, 2008 and Mar. 30, 2009,
the disclosure of which is hereby incorporated by reference herein in its
entirety.

TECHNICAL FIELD

[0002] This disclosure relates to the process for a continuous method and
system for lamination of polarizing films on to substrates used to
fabricate LCD (Liquid-Crystal Display) displays.

BACKGROUND

[0003] For a liquid-crystal display element to function, the direction of
orientation of liquid-crystal molecules and the direction of polarization
of the polarizer must be set in a particular relation to each other. In
liquid-crystal display element technologies, LCDs using a TN (Twisted
Nematic) type liquid-crystal were the first to be put into practical use.
Recently, LCDs using a VA (Vertical Alignment) type liquid-crystal, an
IPS (Inplane Switching) type liquid-crystal etc. were put into practical
use. Although a technical explanation is omitted, in an LCD using such
TN-type liquid-crystal panel, liquid-crystal molecules are provided
between two upper and lower orientation films having respective rubbing
directions on the inner surfaces of the substrates of the liquid-crystal
panel. This means that the liquid-crystal molecules are twisted by 90
degrees along the optical axis so that, when a voltage is applied, the
liquid-crystal molecules are aligned in a direction perpendicular to the
orientation films. However, in the case where the LCD is designed to
allow images of the same quality to be seen from right and left sides of
a display screen as those view from directly in front of the display
screen, the direction of rubbing on the orientation film at the
viewing-side must be 45 degrees (the rubbing direction of the other
orientation film being 135 degrees). It is therefore necessary that the
polarizing sheets made from the polarizing composite films as shown in
FIGS. 1A and 1B, be laminated respectively on the front and back sides of
the liquid-crystal panel with polarizers respectively oriented in
directions inclined respectively by 45 degree with respect to a
lengthwise or widthwise direction of the display screen so as to conform
to the rubbing directions.

[0004] Therefore, in a polarizing sheet for use in producing a
liquid-crystal element of a TN-type liquid-crystal panel, it is required
that the optical film is punched-out or cut into a rectangular-shaped
sheet having a long side or a short side determined in accordance with
the size of the TN liquid-crystal panel, and inclined by 45 degrees with
respect to the orientation direction of the polarizer produced by
stretching in the lengthwise or widthwise direction. This is described in
Japanese Laid-Open Patent Publication No. JP 2003-161935A or Japanese
Patent No. 3616866B. The width of the sheet to be processed into the
rectangular shape, that is, the short side of the sheet, is smaller than
the width of the continuous web.

[0005] The punching or cutting the optical film sheet into the
rectangular-shaped sheet from the continuous web of an optical film may
be collectively referred to as "individualized sheets" or "a method and
system for manufacturing individualized sheets" for liquid-crystal
display elements. The optical film sheet thus punched-out or cut is
produced by punching or cutting not only the surface protection film
contained in the optical film but also the carrier film protecting the
exposed surface of the adhesive layer in the polarizing composite film
together. The integrally punched-out or cut carrier film sheet may be
referred to as "separator", rather than "carrier film sheet". Thus, the
manufacturing process of the liquid-crystal display elements includes the
first step of peeling the separator from each of optical film sheet to
have the adhesive layer of the polarizing sheet exposed. Subsequently,
the optical film sheet each having the adhesive layer exposed are
conveyed one-by-one by for example under a vacuum suction irrespective of
whether the surface protective film sheets are laminated or not, and
laminated to respective ones of a plurality of liquid-crystal panels.
According to the abovementioned manufacturing process of the
liquid-crystal display elements, it has been required that the integrally
punched-out or cut sheet from the continuous web of optical film is in
the form of an individualized sheet having four trimmed sides and a
certain level of stiffness of less deflection or bend and which can be
conveyed and laminated easily. During the initial period in the history
of the manufacturing process of the liquid-crystal display elements, this
optical film sheet or the polarizing sheet contained in the optical film
sheet was generally known as a "polarizing plate" which is still used as
a common name.

[0006] In the manufacturing process of TN-type liquid-crystal display
elements, an optical film fed out from a roll of the optical film
laminate is integrally and sequentially punched-out or cut in a direction
transverse to the feed direction. However, in this case, it is impossible
to obtain a finished liquid crystal display element simply by
sequentially laminating the sheets formed to respective ones of a
plurality of liquid-crystal panels. This is because the sheets each
formed with a long or short side extending in a direction 45 degrees
cannot be laminated sequentially to respective ones of the liquid-crystal
panels W with the same posture. Therefore, to provide a finished
liquid-crystal display element by transporting a polarizing sheet to a
position for lamination with a liquid-crystal panel, and then laminating
the polarizing sheet to the liquid-crystal panel, an optical film having
a width greater than a long side of a liquid-crystal panel is fed out in
a lengthwise direction, and punched-out at an angled direction of 45
degrees with respect to the lengthwise direction for each of the optical
film, using for example a die, into a plurality of individual sheets, and
appropriately fed to the laminating process of the liquid-crystal panel
as shown in Japanese Laid-Open Patent Publication No. JP 2003-161935A or
Japanese Patent 3616866 B. Alternatively, an optical film having a
substantial longitudinal length may be provided by preparing a continuous
web of optical film having a substantially large width and punching or
cutting the web at an angle of 45 degrees with respect to the
longitudinal direction to provide a film sheet which can be used as an
optical film having a substantial length, or may be provided by
connecting together a plurality of such obliquely cut sheets of the
optical film, as shown in Japanese Patent Publication No. 62-14810 B, and
the optical film as produced in such process of forming sheets from an
optical film having the width of the liquid-crystal panel is then
continuously fed and cut in the widthwise direction with respect to its
feeding direction to provide a plurality of sheet strips each having a
required length and each including a plurality of polarizing sheet, the
plurality of polarizing sheets in the sheet strip being then laminated to
respective ones of a plurality of liquid-crystal panels sequentially
conveyed to provide completed liquid-crystal display elements. At any
rate, the above techniques are not beyond the system for manufacturing
individualized sheets.

[0007] Japanese Patent Publication No. 62-14810 B was published before the
VA-type liquid-crystal and the IPS-type liquid-crystal are brought into
practical use and discloses an apparatus to produce a liquid-crystal
panel by sequentially laminating a plurality of sheets formed into a
required length onto respective ones of a plurality of liquid-crystal
panels while continuously feeding an optical film containing a polarizing
composite film. Japanese Patent Publication No. 62-14810 B discloses a
technique of continuously feeding an optical film which comprises a
polarizing composite film (called "elongated polarizing plate") and a
separator for protecting an adhesive layer on the polarizing composite
film, "cutting only a polarizing plate 4 and an adhesive layer while
leaving a separator uncut (hereinafter referred to as "half-cut")",
removing defective polarizing sheets formed in the course of the feeding,
sequentially laminating the peeled sheets to the liquid-crystal panels
(called "liquid-crystal cells") for constituting small-size display
screens of an electronic calculators or the like, while peeling the
separator from the polarizing sheets. The apparatus is a labeler unit
which produces an LCD using a TN-type liquid-crystal. Thus, the optical
film to be used must be an elongated sheet produced from an optical film
cut it in a direction 45 degrees oblique to the longitudinal direction of
the optical film with a width corresponding to the liquid-crystal panel.
Therefore, this apparatus cannot be applied directly to a manufacturing
apparatus adapted to perform steps of continuously forming a plurality of
polarizing sheets from an optical film having a laminated structure and
laminating respective sheets to respective ones of the liquid-crystal
panel using VA-type liquid-crystal and the IPS-type liquid-crystal to
make a liquid-crystal display element because of the width of optical
film required.

[0008] Automation of manufacturing process of liquid-crystal display
elements using individualized sheets is generally described below. For
example, in Japanese Laid-Open Patent Publication No. 2002-23151A.
Flexible individualized sheets tend to be bowed or warped by being bent
or distorted at its edge portions, and such tendencies have caused a
serious technical impediment to accuracy and speed in registration and
lamination with liquid-crystal panels. Thus, it will be understood that
the individualized sheet is required to have a certain level of thickness
and stiffness to facilitate transport under suction and lamination to the
liquid-crystal panel. For example, Japanese Laid-Open Patent Publication
No. 2004-144913A, Japanese Laid-Open Patent Publication No. 2005-298208A
or Japanese Laid-Open Patent Publication No. 2006-58411A disclose
measures for addressing such technical problems.

[0009] On the other hand, the VA-type and IPS-type liquid-crystal panels
are not designed to have a twisted structure of liquid-crystal molecules.
Thus, in producing liquid-crystal display elements using these types of
liquid-crystal panels, it is no longer required to have the polarization
axis of the polarizing sheet oriented 45 degrees. In the case of
liquid-crystal display elements using these types of liquid-crystal
panels, the liquid-crystal display element is formed by applying the
polarizing sheets to the opposite sides of the liquid-crystal display
panel oriented with their polarization axes crossed at 90 degrees each
other. In the case of the VA-type and IPS-type liquid-crystal panels,
with respect to the viewing angle characteristics, maximum contrast can
be obtained along the direction of the polarizing axis of the polarizing
sheet, so that it is preferable that the sheets have optical axes
oriented in parallel with the longitudinal or transverse direction of the
liquid-crystal panel from the technical view point of symmetry of the
viewing angle characteristics and visibility. Thus, these sheets to be
applied to the liquid-crystal panel have a feature that the optical film
including a polarizing composite film which has been subjected to
longitudinal or transverse stretching can be continuously fed out from a
roll and cut along transverse lines with respect to the feed direction of
the optical film to sequentially produce rectangular sheets including the
polarizing sheets having same width as the optical film width.

[0010] Because of the improved viewing angle characteristics, VA-type or
IPS-type liquid-crystal are more widely adopted than the TN-type. In view
of such trend in environments of technical developments, proposals have
been made such as the one described in Japanese Laid-Open Patent
Publication No. 2004-361741A which is a technique for enhancing
manufacturing efficiency based on use of the VA-type or IPS-type
liquid-crystal panels and comprises steps of continuously feeding an
optical film, cutting the optical film in conformity to the size of a
liquid-crystal panel and sequentially laminating a plurality of cut
rectangular sheets comprising the polarizing sheets which have been
produced by the cutting step to respective ones of a plurality of the
liquid-crystal panels.

[0011] However, the mainstream of manufacture of liquid-crystal display
elements is still based on manufacturing technology utilizing
individualized sheets, due to the following technical problems. In
manufacturing liquid-crystal display elements, a critical technical
challenge is to detect any defect which may otherwise be retained in the
display elements to be formed, and to prevent any defective product from
being produced. This makes it possible to significantly improve
manufacturing yield. Most of the product defects primarily arise from
defects in the polarizing composite film contained in the optical film.
However, it is not practical to provide an optical film after completely
removing all defects contained in individual films before they are
laminated together to form the optical film. The reason is that,
observation of the polarizer, protective film laminated on the polarizer
and an adhesive layer formed on the polarizing composite film indicates
that there are various kinds of defects, including defects inherent in
the PVA film of the polarizer itself, defects arose in connection with
the lamination of the protective film to the polarizer or defects
generated in the adhesive layer of the formed polarizing composite film,
distributed in 20 to 200 positions over a unit length of the polarizing
composite film of 1000 m. This means that under existing circumstances,
it is extremely difficult to produce a defect-free optical film. It is
not permitted to use an optical film sheet having visible flaws or
defects as a sheet for television even if such a flaw or defect is small.
Therefore, if lengths of the polarizing composite film with defects are
used to form a display and a display requires 1 m of film, 20 to 200
defective liquid-crystal display elements out of 1,000 products will be
produced.

[0012] A proposed preliminary inspection apparatus for a polarizing
composite film, is disclosed, for example, in Japanese Patent No.
3974400B, Japanese Laid-Open Patent Publication Nos. 2005-62165A and
2007-64989A.

[0013] Japanese Laid-Open Patent Publication 2007-140046A discloses a
method wherein the method comprises peeling a carrier film (called
"releasable film") from an optical film (called "polarizing plate stock")
fed out continuously from a roll of an optical film laminate to expose a
polarizing composite film (called "polarizing plate") having an adhesive
layer; detecting a defect or defects present in the polarizing composite
film; punching or cutting only normal regions of a polarizing composite
film into a rectangular shape, while leaving the defective region or
regions of the polarizing composite film untouched. Japanese Patent
Application No. 2007-266200 discloses an invention relating to a method
and system for laminating a polarizing film sheet to a liquid-crystal
panel. The method and an apparatus disclosed in Japanese Patent
Application No. 2007-266200, however, require that steps cause not only
substantial complexity in the entire system for laminating but also an
increase in the number of steps and difficulty in control for each step,
and therefore, cause corresponding reduction in the manufacturing speed.

[0014] The present disclosure has been made based on the above related
disclosures and through intensive researches and considerations for
significantly enhancing product accuracy and manufacturing speed, and
drastically improving production yield, in the manufacture of
liquid-crystal display elements.

SUMMARY

[0015] The present disclosure is based on findings that solutions of the
aforementioned technical problems can be achieved in a continuous
manufacture of liquid-crystal display elements by a process wherein a
continuous web of an optical film is provided, the optical film having a
width corresponding to the width of the liquid crystal panel having
predefined dimensions and at least comprising a polarizer film having an
adhesive layer thereon and a carrier film releasably attached to the
adhesive layer, the continuous web of optical film having a plurality of
defective-polarizing-sheet slitting positions and normal-polarizing-sheet
slitting positions defined thereon in the form of lines extending in the
widthwise direction of the continuous web of optical film, based on
positions of one or more defects present in the continuous web of optical
film and detected through a preliminary inspection of a polarizing
composite film, the defective-polarizing-sheet slitting positions being
for defining regions containing one or more defects and the
normal-polarizing-sheet slitting positions being for defining regions
having no defect, the defective-polarizing-sheet slitting positions and
the normal-polarizing-sheet slitting positions being recorded on the web
as encoded information, wherein individualized polarizing film sheets are
formed from the continuous web of optical film to have dimensions
corresponding to those of the liquid crystal panels and applied to the
liquid crystal panels to form liquid crystal display elements, wherein
the continuous web of optical film is continuously fed to a lamination
station while measuring a feed distance of the continuous web and
calculating the feed-length measurement data based on the feed distance,
and reading the encoded information recorded on the continuous web,
wherein a plurality of slit-lines are formed in the continuous web by
slitting the continuous web from the surface opposite to the carrier film
to a depth reaching the surface of the carrier film adjacent to the
adhesive layer, along the slitting positions, based on the encoded
information and the feed-length measurement data, when the slitting
position defined in the continuous web thereon comes to a slitting
station, the encoded information being used for determining whether the
polarizing sheets being formed between an adjacent pair of the slit-lines
sequentially formed in the continuous web, is a defective polarizing
sheet having defects or a normal polarizing sheet having no defect,
wherein the polarizing sheet determined to be the normal polarizing
sheet, among the polarizing sheets formed between an adjacent pair of the
slit-lines sequentially formed in the continuous web of optical film, is
then peeled from the carrier film, and transported to the lamination
station, wherein a liquid-crystal panel is transported to the lamination
station in synchronization with the transportation of the normal
polarizing sheet to the lamination station and the normal polarizing
sheet is applied to the liquid-crystal panel.

[0016] The disclosure provides a continuous manufacturing method and
system for liquid-crystal display elements. The system and method uses a
continuous web of optical film comprising a polarizer film having an
adhesive layer thereon a carrier film and information encoded thereon,
the encoded information indicating positions for slitting the continuous
web of optical film based on positions of defects present in the
continuous web of optical film.

[0017] The system and method continuously feeds the continuous web of
optical film to a lamination station, measures a feed distance of the
continuous web, calculates the feed-length measurement data based on the
feed distance, reads the encoded information recorded on the continuous
web.

[0018] The system and method forms a plurality of slit-lines in the
continuous web by slitting the continuous web from the surface opposite
to the carrier film to a depth reaching the surface of the carrier film
adjacent to the adhesive layer, along the slitting positions. The
position of the slitting positions based on the encoded information and
the feed-length measurement data. The system and method uses the encoded
information for determining whether the polarizing sheets being formed
between an adjacent pair of the slit-lines sequentially formed in the
continuous web is a defective polarizing sheet having one or more defects
or a normal polarizing sheet having no defect, peels the polarizing sheet
determined to be the normal polarizing sheet, among the polarizing sheets
formed between an adjacent pair of the slit-lines sequentially formed in
the continuous web of optical film, from the carrier film. The system and
method transports the peeled polarizing sheets to the lamination station;
sequentially transports liquid-crystal panels to the lamination station
in synchronization with the transportation of the normal polarizing
sheets to the lamination station; and applies the polarizing sheets to
respective ones of the liquid-crystal panel in a sequential manner.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure is illustrated by way of example, and not by
limitation, in the figures of the accompanying drawings in which elements
having the same reference numeral designations represent like elements
throughout and wherein:

[0020] FIG. 1A and FIG. 1B are schematic diagrams showing the structure of
an optical film for use in manufacturing of a liquid-crystal display
element according to at least one embodiment.

[0021] FIG. 2 illustrates a typical example of a liquid-crystal display
element for a widescreen television having a diagonal screen size of 42
inches.

[0022]FIG. 3 is a schematic diagram showing defective regions including
defects existing in an optical film for use in a liquid-crystal display
element, and normal regions having no defect according to at least one
embodiment.

[0023] FIG. 4 is a conceptual diagram showing a system for continuously
manufacturing liquid-crystal display elements wherein polarizing sheets
are laminated on liquid-crystal panels through inspection of defects in
the polarizing composite films, without interrupting the feed of the
continuous web of optical film being fed.

[0024]FIG. 5 is a conceptual diagram showing a continuous manufacturing
system for liquid-crystal display elements according to one embodiment,
wherein the system comprises an optical-film feed apparatus for feeding a
web of an optical film from a roll of the optical film laminate, and a
liquid-crystal-panel conveyance apparatus for conveying a liquid-crystal
panel to be laminated with a normal polarizing sheet cut by forming slit
lines in the continuous web of optical film being fed.

[0025]FIG. 6 is a flow chart showing a manufacturing process or steps in
continuous manufacturing system for liquid-crystal display elements in
FIG. 5.

[0026]FIG. 7 is a schematic diagram showing the relationship between a
control unit for controlling device of the optical-film feed apparatus
and the liquid-crystal-panel conveyance apparatus illustrated in FIG. 5,
and encoded information read by a reading unit and processed by an
information processing device in the continuous manufacturing system for
liquid-crystal display elements, according to at least one embodiment.

[0027]FIG. 8 is a schematic diagram showing a defective-polarizing-sheet
removal unit comprising (1) a dummy-film drive mechanism disposed in a
feed passage for an optical film or (2) a dummy-film drive mechanism
adapted to be moved in and away from a gap between a pair of lamination
rollers movable closer to and away from each other in the continuous
manufacturing system for liquid-crystal display elements, according to at
least one embodiment.

[0028]FIG. 9 is a schematic diagram showing the operation of a slitting
position checkup unit, together with the inspection method for checking a
difference between feed-length measurement data on an optical-film feed
length measured based on a slit line formed in the continuous web of
optical film being fed, and the position for forming a slit-line read by
a reading device in the continuous manufacturing system for
liquid-crystal display elements, according to at least one embodiment.

[0029] FIG. 10 is a schematic diagram showing the state when encoded
information recorded on the continuous web of optical film is read by the
reading unit, and a pre-alignment unit, a final-alignment unit, a
lamination position-directed conveyance unit and a panel-edge detection
unit in the liquid-crystal-panel conveyance apparatus are controlled
based on the encoded information to allow a liquid-crystal panel to be
conveyed in a controlled posture in the continuous manufacturing system
for liquid-crystal display elements, according to at least one
embodiment.

[0030] FIG. 11 is a schematic diagram showing a lamination unit comprising
a sheet-edge detection unit for detecting a leading edge of a normal
polarizing sheet of a polarizing composite film formed from the
continuous web of optical film, and straight-ahead-posture detection unit
for detecting an alignment with a feed direction of the formed normal
polarizing sheet of the polarizing composite film.

[0031] FIG. 12 is a schematic diagram showing a manufacturing method and
system for a roll of an optical film laminate according to at least one
embodiment.

[0032]FIG. 13 is a schematic diagram showing a manufacturing method and
system for a roll of an optical film laminate according to at least one
embodiment.

[0033]FIG. 14 is a schematic diagram showing a manufacturing method and
system for a roll of an optical film laminate according to at least one
embodiment.

[0034] FIG. 15 is a flowchart showing a manufacturing process or process
steps in the manufacturing method and system for a roll of an optical
film laminate illustrated in FIG. 12.

[0035]FIG. 16 is a flowchart showing a manufacturing process or process
steps in the manufacturing method and system for a roll of an optical
film laminate illustrated in FIG. 13.

[0036]FIG. 17 is a flowchart showing a manufacturing process or process
steps in the manufacturing method and system for a roll of an optical
film laminate illustrated in FIG. 14.

[0037] FIG. 18 is a schematic diagram showing a technique of calculating a
position for forming a slit line in a continuous web of an optical film
being fed to segment a region of a polarizing composite film into a
defective region and a normal region, in the continuous manufacturing
system for liquid-crystal display element, according to at least one
embodiment.

[0038]FIG. 19 is a flowchart showing a technique of calculating a
position for forming a slit line in a continuous web of an optical film
being fed.

[0039] FIG. 20 is a flowchart showing another technique of calculating a
position for forming a slit line in a continuous web of an optical film
being fed.

[0040]FIG. 21 is a flowchart showing yet another technique of calculating
a position for forming a slit line in a continuous web of an optical film
being fed.

[0041]FIG. 22 is a table showing an example of encoding and recording of
positional information to an optical film, in the continuous
manufacturing system for liquid-crystal display element, according to at
least one embodiment.

[0042]FIG. 23 is a diagram showing an example of encoding of a position
for forming a slit line in an optical film, in a technique of
identification information or defect-including information Xγ in
FIG. 19, in the continuous manufacturing system for liquid-crystal
display element, according to at least one embodiment.

[0043]FIG. 24 is a diagram showing an example of encoding of a
slit-position information indicative of the position for forming a slit
line in an optical film, in a technique of modifying a distance to a
next-slit-line formation position to (X'+X0), wherein X0'>X0, in FIG.
20, in the continuous manufacturing system for liquid-crystal display
element, according to at least one embodiment.

[0044]FIG. 25 is a diagram showing an example of encoding of a
slit-position information indicative of the position for forming a slit
line in an optical film, in a technique of modifying a distance to a
next-slit-line formation position to [(X'+X0)/m], wherein m=2 or more, in
FIG. 21, in the continuous manufacturing system for liquid-crystal
display element, according to at least one embodiment.

[0045]FIG. 26 is a schematic diagram showing a manufacturing system for a
roll of an optical film laminate having two inspection units, according
to the embodiment illustrated in FIG. 13.

[0046]FIG. 27 is a schematic diagram showing a manufacturing system for a
roll of an optical film laminate having four inspection units, according
to the embodiment illustrated in FIG. 14.

[0047]FIG. 28 is a table showing a defect inspection device, a type of
defect and a defect detection method.

[0125] In the following detailed description, for purposes of explanation,
numerous specific details are set forth in order to provide a thorough
understanding of the disclosed embodiments. It will be apparent, however,
that the disclosed embodiments may be practiced without these specific
details. In other instances, well-known structures and devices are
schematically shown in order to simplify the drawing.

[0126] Taking a widescreen television having a diagonal screen size of 42
inches as an example, a liquid-crystal panel W therefore comprises a
layered liquid-crystal panel which includes a pair of rectangular-shaped
substrates each having a size of about 540 to 560 mm in length×
about 950 to 970 mm in width×about 0.7 mm (700 μm) in thickness,
and a liquid-crystal layer having a thickness of about 5 μm having a
transparent electrode, a color filter etc. and sandwiched between the
glass substrates, as shown in FIG. 2. Therefore, the thickness of the
liquid-crystal panel W itself is about 1.4 mm (1400 μm). The
liquid-crystal display element typically has a polarizing sheet 11'
commonly referred to as "polarizing plate" adhesively applied to each of
a front side (viewing side) and a back side (backlight side) of the
liquid-crystal panel W thereof. The polarizing sheet 11' is formed from a
polarizing composite film 11 included in a continuous web of a flexible
optical film 10 of a laminated structure, as shown in the perspective
view at FIG. 1A, to have a rectangular shape with a size of 520 to 540 mm
in length×930 to 950 mm in width, as shown in the perspective view
FIG. 1B and in FIG. 2.

[0127] Although the substrates are usually formed from glass, this
disclosure is not limited to glass substrates. Other materials such as
plastics or composites made from various glass and plastic materials may
be used to form either one or both of the substrates.

[0128] The continuous web of optical film 10 for use in forming the
polarizing sheet 11' to be laminated to the liquid-crystal panel W
typically consists of a flexible film of a laminated structure which
comprises the polarizing composite film 11, surface-protection film 13
having an adhesive surface, and a carrier film 14. The polarizing
composite film 11 shows a polarizing function, and generally includes a
continuous layer of polarizer, two protective films laminated on
respective ones of the opposite surfaces of the continuous polarizer
layer, and an acrylic adhesive layer 12 formed on one side of the
continuous polarizer layer which is to be applied to the liquid-crystal
panel W. The carrier film 14 is a film releasably laminated to the
adhesive layer 12 to provide a function of protecting the exposed side of
the adhesive layer 12 of the polarizing composite film 11. The polarizing
composite film 11 is formed through the following process, for example. A
continuous polarizer layer having a thickness of 20 to 30 μm is first
formed by subjecting a PVA (polyvinyl alcohol)-based film having a
thickness of about 50 to 80 μm to a dyeing treatment using iodine and
a cross-linking treatment, and subjecting the resultant PVA-based film to
an orientation treatment based on stretching in a lengthwise or widthwise
direction thereof. As a result, the iodine complex is oriented in the
direction parallel to the stretching direction of the PVA-based film to
acquire a property of absorbing a polarized light having a plane of
oscillation matching with the orientation of the iodine complex to
thereby provide a polarizer having absorption axes in the direction
parallel to the stretching direction. Thus, in order to produce a
polarizer having an excellent optical property in addition to excellent
uniformity and accuracy, it is desirable that the stretching direction of
the PVA-based film corresponds to the lengthwise or widthwise directions
of the film. Therefore, generally, the absorption axis of a polarizer or
an optical film including such polarizer is parallel to the lengthwise
direction of the continuous web, and the polarizing axis is in the
widthwise direction perpendicular to the absorption axis. Then, the
protective film is laminated to one or each of the opposite surfaces of
the formed continuous polarizer layer through an adhesive. Finally, on
one side of the continuous polarizer layer with the protective film
laminated, the acrylic adhesive layer 12 to be applied to the
liquid-crystal panel W is formed. Generally, a transparent TAC
(triacetylcellulose)-based film having a thickness of about 40 to 80
μm is often used as the protective film for protecting the continuous
polarizer layer. In the following description, the continuous layer of
polarizer may be simply referred to as "polarizer".

[0129] According to the definition of terms in "SEMI (Semiconductor
Equipment and Materials International) Draft Document" on polarizing
films for flat-panel display elements including liquid-crystal display
elements (FPD Polarizing Films), the term corresponding to the
"polarizing composite film and layer" constituting an optical film for
use in a liquid-crystal display element is referred to as "films and
layer composing polarizing films". Thus, the polarizing composite film 11
in the perspective view at FIG. 1A is interpreted as corresponding to the
"films composing polarizing films". The polarizing sheet 11' in the
perspective view at FIG. 1B which is formed in a rectangular shape from
the polarizing composite film 11, corresponds to "polarizing films", so
that it may be preferable to apply the term "polarizing sheet" to the
latter, rather than the commonly called name "polarizing plate". In the
following description, a film including a polarizer, a protective film
laminated on one or both of opposite surfaces of the polarizer, and an
adhesive layer formed on one side of the polarizer to be laminated to a
liquid-crystal panel W, will be referred to as "polarizing composite
film", and a sheet commonly called by the name "polarizing plate", which
is formed in a rectangular shape from the polarizing composite film, will
be referred to as "polarizing sheet" or simply "sheet". In addition, when
a sheet is formed from a polarizing composite film having a
surface-protection film and a carrier film attached thereto, and when
this sheet has to be distinguished from "a polarizing sheet", the former
is referred to as "an optical film sheet", and a sheet formed from the
surface-protection film or the carrier film included in the composite
film is respectively referred to as "a surface-protection film sheet" or
"a carrier film sheet".

[0130] The thickness of the polarizing composite film 11 generally has a
thickness of about 110 to 220 μm. The polarizing composite film 11 is
generally comprised of a polarizer having a thickness of about 20 to 30
μm, two protection films which a total thickness may be about 80 to
160 μm when the protective films are laminated on respective ones of
opposite surfaces of the polarizer, and an adhesive layer 12 which
thickness formed on one side of the polarizer to be laminated to a
liquid-crystal panel W is about 10 to 30 μm. The polarizing composite
films 11 are laminated to respective ones of the front and back sides of
the liquid-crystal panel W with the adhesive layer 12 in such a manner
that polarizing axes intersect each other at an angle of 90 degrees.
Thus, in manufacturing a liquid-crystal display element for a widescreen
television having a diagonal screen size of 42 inch, on an assumption
that a thickness of a liquid-crystal panel itself is about 1400 μm,
and since a thickness of each of the polarizing composite films 11 is in
the range of 110 to 220 μm, the liquid-crystal display element itself
has an overall thickness of about 1620 to 1840 μm. The thickness of
the liquid-crystal display element is still within 2.0 mm or less. In
this case, the ratio of the thickness of the liquid-crystal display
element to the overall thickness of the liquid-crystal panel W and the
sheet 11' is about 10:1.5 to 10:3. If use is made of a polarizing
composite film 11 having a protective film laminated to only one surface
of the polarizer, and an adhesive layer formed on the other surface of
the polarizer, from the view point of reducing the thickness of the
liquid-crystal display element, the thickness of the polarizing composite
film 11 itself can be reduced to 70 to 140 μm, so that an overall
thickness of the resultant liquid-crystal display element is reduced to a
range of about 1540 to 1680 μm. The ratio of a thickness of the
liquid-crystal element to that of the liquid-crystal panel W and the
sheet 11' will be in the range of about 10:1 to 10:2.

[0131] A continuous web of an optical film 10 for use in a liquid-crystal
display element has a structure as shown in the perspective view at FIG.
1A. The structure of the continuous web of optical film 10 will be
briefly described below, in connection with a manufacturing process
thereof. A surface-protection film 13 with an adhesive surface having a
thickness of about 60 to 70 μm is releasably laminated to the surface
of a polarizing composite film 11 devoid of an adhesive layer, and a
carrier film 14 is releasably laminated to an adhesive layer 12 provided
on the surface of a polarizing composite film 11 which is to be laminated
to the liquid-crystal panel W, for providing a function of protecting the
adhesive layer 12. Typically, a PET (polyethylene terephthalate)-based
film is used for each of the surface-protection film 13 and the carrier
film 14. During the manufacturing process of the liquid-crystal display
element, the carrier film 14 generally serves as a carrying medium
(carrier) for the polarizing composite film 11, as well as the means to
protect the adhesive layer 12. A film having such functions will
hereinafter be referred to as a "carrier film". Both of the
surface-protection film 13 and the carrier film 14 are so-called
"manufacturing-process materials" which are to be peeled and removed
prior to the final stage of the manufacturing process of the
liquid-crystal display elements, and which are to be used for protecting
the non-adhesive surface from being soiled or damaged, and also
protecting the exposed surface of the adhesive layer, of the polarizing
composite film 11, during the manufacturing process of the liquid-crystal
display elements.

[0132] In the polarizing composite film 11, one of the protective films
for protecting the polarizer may be replaced with a phase difference film
made of a cycloolefin-based polymer, a TAC-based polymer or the like and
having an optical compensation function. It may further be provided as a
layer of a transparent substrate, such as a TAC-based substrate, having a
polymer material, such as a polyester-based polymer or a polyimide-based
polymer applied/arranged thereto and then cured. Further, in the case of
a polarizing composite film to be laminated to the backlight side of the
liquid-crystal display element, it may be possible to provide an
additional function by laminating a brightness enhancement film to the
backlight side protective film of the polarizer. In addition, regarding
the structure of the polarizing composite film 11, there have been
proposed various other variations, such as a technique of laminating a
TAC-based film to one of opposite surfaces of the polarizer and
laminating a PET film to the other surface of the polarizer.

[0133] One of the methods for providing a polarizing sheet 11' including a
polarizer and a protective film laminated on one or both of opposite
surfaces of the polarizer devoid of an adhesive layer for attaching to a
liquid-crystal panel W comprises a step of laminating a carrier film 14
having a transferable adhesive layer formed thereon, to the surface of
the polarizing sheet 11' to be laminated to the liquid-crystal panel W. A
specific transfer technique is as follows. In a manufacturing process of
the carrier film 14, the carrier film is subjected to a releasing
treatment at the surface which is to be laminated to the polarizing sheet
11' at the surface of the polarizing sheet 11' which is to be laminated
to the liquid-crystal panel and then a solvent containing adhesive is
applied to the treated surface and dried to form an adhesive layer on the
carrier film 14. Then, the carrier film 14 having the formed adhesive
layer is laminated to the polarizing sheet 11', for example, while
continuously feeding out the carrier film 14 and feeding out the
polarizing sheet 11' in the same manner, so that the adhesive layer
formed on the carrier film 14 is transferred to the polarizing sheet 11',
and the adhesive layer 12 is formed. Instead of forming the adhesive
layer in this manner, the adhesive layer 12 may be formed by directly
applying a solvent containing adhesive to the surface of the polarizing
sheet 11' to be laminated to the liquid-crystal panel, and drying the
same.

[0134] The surface-protection film 13 typically has an adhesive surface.
Unlike the adhesive layer 12 on the polarizing composite film 11, the
adhesive surface must be peeled from a polarizing sheet 11' of the
polarizing composite film together with a surface-protection film sheet
(not shown) when the surface-protection film sheet is peeled and removed
from the polarizing sheet 11' during the manufacturing process of the
liquid-crystal display elements. The reason is that the
surface-protection film sheet which is formed together with the
polarizing sheet 11' is adapted for protecting the surface of the
polarizing sheet 11' devoid of an adhesive layer 12 from the risk of
being soiled or damaged, but not an adhesive surface to be transferred to
the surface of the polarizing sheet 11'. The perspective view at FIG. 1B
shows the state after the surface-protection film sheet is peeled and
removed. It should further be noted that, irrespective of whether the
polarizing composite film 11 has a surface-protection film 13 laminated
thereon, it may be possible to provide the polarizing composite film 11
at the surface of the protective film on the front side of the polarizing
composite film 11 with a hard coat treatment for protecting the outermost
surface of the liquid-crystal display element, and/or a surface treatment
for obtaining an anti-glare effect or the like, such as an anti-glare
treatment.

[0135] As described above, the polarization axes of the polarizing
composite films laminated to respective ones of front and rear surfaces
of the liquid-crystal panel are oriented in substantially parallel with
respect to the direction of the sides of the liquid-crystal panel which
extend in directions crossed by 90 degrees from each other, so that, in
using the VA-type and IPS-type liquid-crystal panels, there is no
constraint regarding the orientation of the two polarizing film sheets
with respective to the direction of the long or short side of the
liquid-crystal display element, in order to obtain an increased viewing
angle characteristics. Therefore, with such VA-type and IPS-type
liquid-crystal panels, it becomes possible to realize a continuous
manufacturing of the liquid-crystal display elements wherein a web of an
optical film containing a polarizing composite film is continuously
supplied and cut in the direction transverse to the feed direction of the
optical film to form individualized polarizing sheets, and such
polarizing sheets are sequentially laminated to respective ones of a
plurality of liquid-crystal panels. In addition, if it becomes possible
to define, while the optical film containing the polarizing composite
film is being continuously fed, defective polarizing sheets including one
or more defects detected by a preliminary inspection of the polarizing
composite film contained in the optical film as well as normal polarizing
sheets including no defect, and to advance only the normal polarizing
sheets to the lamination station for lamination with respective ones of a
plurality of sequentially supplied liquid-crystal panels to make
liquid-crystal display elements, without interrupting the feed of the
optical film, there will be remarkable improvements in accomplishing
enhanced product accuracy and increased manufacturing speed as well as
significantly improved production yield in the manufacture of
liquid-crystal display elements.

[0136] The present disclosure is directed, as described later, to a
continuous manufacture of liquid-crystal display elements wherein a
continuous web of an optical film is provided, the optical film having a
width corresponding to the width of the liquid crystal panel having
predefined dimensions and at least comprising a polarizer film having an
adhesive layer thereon and a carrier film releasably attached to the
adhesive layer, the continuous web of optical film having a plurality of
defective-polarizing-sheet slitting positions and normal-polarizing-sheet
slitting positions defined thereon in the form of lines extending in the
widthwise direction of the continuous web of optical film, based on
positions of defects present in the continuous web of optical film and
detected through a preliminary inspection of a polarizing composite film,
the defective-polarizing-sheet slitting positions being for defining
regions containing one or more defects and the normal-polarizing-sheet
slitting positions being for defining regions having no defect, the
defective-polarizing-sheet slitting positions and the
normal-polarizing-sheet slitting positions being recorded on the web as
encoded information, wherein individualized polarizing film sheets being
formed from the continuous web of optical film to have dimensions
corresponding to those of the liquid crystal panels and applied to the
liquid crystal panels to form liquid crystal display elements, wherein
the continuous web of optical film is continuously fed to a lamination
station while measuring a feed distance of the continuous web and
calculating the feed-length measurement data based on the feed distance,
and reading the encoded information recorded on the continuous web,
wherein a plurality of slit-lines are formed in the continuous web by
slitting the continuous web from the surface opposite to the carrier film
to a depth reaching the surface of the carrier film adjacent to the
adhesive layer, along the slitting positions, based on the encoded
information and the feed-length measurement data, when the slitting
position defined in the continuous web thereon comes to a slitting
station, the encoded information being used for determining whether the
polarizing sheets being formed between an adjacent pair of the slit-lines
sequentially formed in the continuous web is a defective polarizing sheet
having defects or a normal polarizing sheet having no defect, wherein the
polarizing sheet determined to be the normal polarizing sheet, among the
polarizing sheets being formed between an adjacent pair of the slit-lines
sequentially formed in the continuous web of optical film is then peeled
from the carrier film, and transported to the lamination station, wherein
a liquid-crystal panel is transported to the lamination station in
synchronization with the transportation of the normal polarizing sheet to
the lamination station and the normal polarizing sheet is applied to the
liquid-crystal panel. Specifically, the technical target of the present
disclosure is to realize an uninterrupted sequential lamination of normal
polarizing sheets to liquid crystal panels by sequentially supplying
formed normal polarizing sheets without any interruption of feed of the
continuous web of optical film by providing means wherein a continuous
web of an optical film containing a polarizing composite film is fed to a
lamination station for lamination with a liquid-crystal panel, followed
by sequentially forming defective polarizing sheets including one or more
defects detected through a preliminary inspection of the polarizing
composite film contained in the optical film and normal polarizing sheets
including no defect respectively, from the continuous web at a slitting
station, while the continuous web is being fed, the formed defective
polarizing sheet being prevented from being laminated to the
liquid-crystal panel.

[0137] Specific embodiments are now described with reference to the
accompanying drawings.

[0138] I. A Continuous Manufacturing System and Method for Liquid-Crystal
Display Elements

[0139] (General Description of a Continuous Manufacturing System for
Liquid-Crystal Display Elements)

[0140]FIG. 5 is a schematic diagram showing a continuous manufacturing
system for liquid-crystal display elements 1, which comprises an
optical-film feed apparatus 100 having a roll of an optical film laminate
for manufacturing liquid-crystal display elements according to at least
one embodiment, and a liquid-crystal-panel conveyance apparatus 300 for
conveying liquid-crystal panels to be laminated with normal polarizing
sheets formed from a continuous web of optical film fed from the roll.
The continuous manufacturing system 1 comprises at least a slitting
station A for forming a plurality of polarizing sheets from the
continuous web of optical film, a removal station C for removing
defective polarizing sheets and a lamination station B for laminating
normal polarizing sheets to liquid-crystal panels, and the lamination
station B and the removal station C may be positioned redundantly as
described later. FIG. 6 is a flowchart showing a manufacturing process or
process steps in the continuous manufacturing system for liquid-crystal
display elements 1 illustrated in FIG. 5.

[0141] The optical-film feed apparatus 100 comprises a support rack 110
for rotatably mounting a roll of optical film laminate 10 according to
one embodiment of the present disclosure, a reading unit 120 for reading
encoded information, a film feed unit 130 including a feed roller, a
speed adjustment unit 140 including a dancer roller for providing a
constant speed film feeding, a slitting unit 150 provided at a slitting
station A for forming a plurality of slits in the continuous web of
optical film in a direction transverse to the feed direction of the
continuous web from the surface opposite to the carrier film to a depth
reaching the adhesive layer surface of the carrier film to form slit
lines, a slit-position check unit 160 provided also at the slitting
station A for checking the formed slit lines, a film feed unit 170
including a feed roller, a speed adjustment unit 180 including a dancer
roller for providing a constant speed film feeding, a
defective-polarizing-sheet removal unit 190 provided at a removal station
C for removing a slit defective polarizing sheet from the carrier film, a
lamination unit 200 provided at a lamination station B including a pair
of lamination rollers for applying a normal polarizing sheet which has
been slit and peeled from the carrier film to a liquid-crystal panel, a
carrier-film take up mechanism 210 for taking up the carrier film, an
sheet-edge detection unit 220 for detecting a leading edge of the normal
polarizing sheet provided also at the lamination station B and an
straight-ahead-posture detection unit 230 for detecting an advance
direction of the normal polarizing sheets having slit lines to be
comprised in the continuous web of optical film.

(Provisions of the Roll of the Optical Film Laminate 10)

[0142] It is preferable that the roll of the optical film laminate 10
according to this embodiment installed in the optical-film feed apparatus
100 has a width approximately equal to a length of a long or short side
of a liquid-crystal panel to which it is applied. It is preferable that a
transparent protective film is used for the protective film laminated on
one or each of the opposite surfaces of the polarizer as shown in the
schematic diagram of FIG. 1A and FIG. 1B. The roll of the optical film
laminate 10 comprises a roll of an optical film laminate comprising a
continuous web of an optical film comprised of a polarizing composite
film 11 including a polarizer having an adhesive layer 12 provided on the
surface of the polarizer which has a transparent protective film
laminated thereon and which is to be attached to a liquid-crystal panel,
a surface-protection film 13 having an adhesive surface which is
releasably laminated on the surface of the polarizing composite film 11
opposite to the surface having the adhesive layer 12, and a carrier film
14 releasably laminated on the adhesive layer 12 of the polarizing
composite film 11. The carrier film 14 is a releasable film adapted to
protect the adhesive layer 12 of the polarizing composite film 11 during
the manufacturing process of liquid-crystal display elements and to be
removed by being taken up when the polarizing sheet formed in the
continuous web of optical film is peeled prior to or during lamination
process for attaching the polarizing sheet to the liquid-crystal panel.
In this embodiment, the term "carrier film" is used since the film has a
function of carrying the normal polarizing sheets in the polarizing
composite film 11 to the lamination station B.

[0143] The roll of the optical film laminate 10 is formed as follows.
Details of the method for manufacturing the roll of the optical film
laminate 10 will be described later. During the manufacturing process of
the roll of the optical film laminate 10, defects existing in the
polarizing composite film 11 of the optical film being continuously fed
are first detected using an inspection unit. Then, based on the detected
locations or coordinate positions of the defects in the polarizing
composite film 11, defective regions and defect-free, normal regions are
defined in the polarizing composite film 11 as shown in FIG. 3. Then,
information including slit-position information and optional
identification information for identifying the defective regions and the
normal regions is recorded on the optical film being continuously fed.
The slit-position information is indicating the positions at which
respective ones of the slit lines are to be formed in the continuous web
of optical film, and the slit lines are formed in pairs by slitting unit
150 at the slitting station A based on the defective and normal regions
of the polarizing composite film 11, during the manufacturing process of
the liquid-crystal display element, in a manner as to slit sequentially
the continuous web of optical film being fed in a direction transverse to
the feed direction of the continuous web to a depth reaching the adhesive
layer surface of the carrier film. The information including the
slit-position information and the optional identification information to
be recorded on the continuous web of optical film is encoded information
created together with or in association with additional information, such
as information relating to the manufacturing lot and the length of the
web in the roll. Preferably, the encoded information is recorded on the
carrier film 14 in the optical film to be continuously fed. It is to be
understood that the encoded information may be recorded on the carrier
film 14 in any of a variety of modes, such as a mode in which encoded
information including all necessary information is recorded on a single
storage location, or a mode in which a plurality of encoded information
locations each including different information are recorded on a
plurality of storage locations at given intervals (e.g., at intervals of
1 m or 100 m). The encoded information may be recorded on the
surface-protection film 13, instead of the carrier film 14. In either
case, the encoded information is configured to be readable by the reading
unit 120 of the continuous manufacturing system 1.

[0144] The slitting unit 150 provided at the slitting station A in the
continuous manufacturing system 1 having the roll of the optical film
laminate 10 mounted thereon is operated, during the manufacturing process
of the liquid-crystal display element, by having the feed-length
measurement data on an optical-film fed-out distance calculated when the
optical film is unrolled from the roll of the optical film laminate 10
related with the slit-position information included in the encoded
information and read by the reading unit 120 of the continuous
manufacturing system 1. The region of the polarizing composite film
defined by respective longitudunally adjacent two slit lines may include
a defect-free normal region having a given length determined by the
length of a side of a liquid-crystal panel to be laminated with the
polarizing composite film, and a defective region having a length
generally less than the given length. During the manufacturing process of
the liquid-crystal display element, the defective region of the
polarizing composite film 11 which is cut along pairs of slit lines by
means of the slitting unit 150 is defined as a defective polarizing sheet
Xβ which is to be removed from the continuous web of optical film
(specifically, the carrier film 14) by the defective-polarizing-sheet
removal unit 190 of the continuous manufacturing system 1 at the removal
station C. The normal region of the polarizing composite film 11 is cut
in the same manner and defined as a normal polarizing sheet Xα
which is to be peeled from the continuous web of optical film
(specifically, the carrier film 14) and laminated to one of opposite
surfaces of a liquid-crystal panel by means of the lamination unit 200 of
the continuous manufacturing system 1 at the lamination station B.

[0145] Referring to FIG. 3, a specific formation of the slit lines into
the polarizing composite film 11 based on the normal region and the
defective region of the polarizing composite film is described as
follows. The length (Xα) of the normal region previously defined in
accordance with the locations or the coordinate positions of defects in
the polarizing composite film 11 is determined to a constant value in
accordance with the length of one of the sides of the liquid-crystal
panel which is to be laminated with the normal polarizing sheet.
Similarly, with respect to the defective region which is also previously
defined, the upstream side slit line for defining the defective region is
defined by the downstream side slit line defining the normal region which
is located immediately upstream side of the defective region, as seen in
the feed direction of the web. Thus, the length (Xβ) of the
defective region is determined by the upstream side slit line and a
downstream side slit line which is formed slightly downstream side of the
location or coordinate position of a defect. Since the length between the
upstream side slit line of the defective region and the location or
coordinate position of defects of the polarizing composite film as seen
in the feed direction may not be fixed, the length (Xβ) of the
defective region varies accordingly. In accordance with one embodiment,
the length (Xβ) of the defective region is determined through an
information processing, when a processing is made for determining the
slit-position information which designates the position at which the slit
line is to be formed, so that it is always different from the length
(Xα) of the normal region, e.g., to establish the relationship
Xβ<Xα, in any case. In accordance with another embodiment,
it may be possible that identification information Xγ is produced
to identify the defective region from the normal region, when the length
(Xβ) of the defective region becomes equal to the length (Xα)
of the normal region. In this case, the produced identification
information Xγ is incorporated into the encoded information
together with and in association with the slit-position information. It
may be possible that the continuous manufacturing apparatus 1 is
configured such that, during the manufacturing process of liquid-crystal
display elements, at the slitting station, the slitting unit 150
functions to form the normal polarizing sheet Xα and the defective
polarizing sheet Xβ according to the slit-position information read
by the reading unit 120, and the defective-polarizing-sheet removal unit
190 at the removal station functions to readily discriminate and remove
only defective polarizing sheets having lengths (Xβ) different from
the length (Xα) of the normal polarizing sheet. In the case where
the encoded information includes the identification information Xγ
for identifying the defective region over the normal region, the
defective-polarizing-sheet removal unit 190 functions, based on the
identification information, to discriminate and remove only defective
polarizing sheets. The specific manufacturing process of the roll of the
optical film laminate 10 used in the continuous manufacturing system 1
will be described later.

[0146] The roll of the optical film laminate 10 is mounted on the support
rack 110 of the continuous manufacturing system 1. Preferably, the
support rack 110 is provided with an encoder (not shown) for determining
the feed length of the optical film, the feed-length measurement data
obtained by the encoder is stored in a storage device 420 of a control
unit 400. Alternatively, a measurement device may additionally be
provided in the optical-film feed apparatus 100 for calculating the feed
length of the continuous web of optical film.

[0147] In operation of the entire system, a roll of dummy film is first
installed on the support rack 110. A continuous web of dummy film is
unrolled from the roll of dummy film under tension by means of first and
second film feed units 130, 170 each including feed rollers. The dummy
film is advanced until its leading edge reaches a position where, under a
normal operation, the carrier film 14 from which the normal polarizing
sheet Xα is peeled, is passed through the lamination unit 200
provided at the lamination station B and taken up by the carrier-film
take up drive mechanism 210. Then, the trailing end of the dummy film is
connected to the leading end of the optical film unrolled from the roll
of the optical film laminate 10, and a supply of the optical film is
initiated. In order to allow the continuous web of optical film to be
maintained at a constant speed under tension even if the feed of the
optical film is temporarily stopped at the slitting station A where the
slit lines are formed in the polarizing composite film by the slitting
unit 150 or at the lamination station B where the normal polarizing sheet
is laminated on a liquid-crystal panel, there are provided first and
second speed adjustment units 140, 180 each including the aforementioned
dancer rollers immediately before these positions.

[0148] In the continuous manufacturing system, assuming that a single roll
of the optical film laminate includes 1000 meters of length of the web of
the laminate for example, and the production capacity of the continuous
manufacturing system 1 amounts to the order of 5,000 to 20,000 meters a
day, a single such continuous manufacturing system 1 will be operated by
being sequentially connected with 5 to 20 rolls of the optical film
laminate in a day. It can be said that the continuous manufacturing
system for liquid-crystal display elements 1 using the roll of the
optical film laminate 10 according to this embodiment to make
liquid-crystal display elements, makes it possible to enhance product
accuracy and double the manufacturing speed compared to the conventional
manufacturing system using individualized sheets, on the condition that a
plurality of liquid-crystal panels W can be sequentially fed without any
problem. In this case, the number of the rolls of the optical film
laminate to be handled will increase significantly, which gives rise to a
new technical need for automatic replacement of the roll of the optical
film laminate.

(Reading and Information Processing of Encoded Information)

[0149] In this embodiment, slit lines are sequentially formed on the
continuous web of optical film leaving the carrier film 14 uncut by the
slitting unit 150 at the slitting station A, the normal polarizing sheet
Xα of the polarizing composite film 11 cut along the adjacent two
of slit lines is then peeled from the carrier film 14 immediately before
the lamination unit 200 at the lamination station B, and the peeled
normal polarizing sheet Xα is laminated to a liquid-crystal panel
through the exposed adhesive layer 12 to make a liquid-crystal display
element. During this process, the carrier film 14 is taken up by the
carrier-film take up drive mechanism 210. Generally, the
surface-protection film 13 is made to be a sheet configuration which is
held together with a normal polarizing sheet Xα of polarizing
composite film 11 which is to be laminated to a liquid-crystal panel, and
the sheet of the surface-protection film is peeled and removed after the
final step including cleaning/drying is carried out on the liquid-crystal
display element to be produced. Both of the carrier film and the
surface-protection film are manufacturing-process materials required for
carrying out the process, but are removed in the final stage of the
manufacturing process and discarded. Thus, it is one of the features of
the roll of the optical film laminate 10 in accordance with this
embodiment to use such a manufacturing-process material as an information
storing medium necessary for the manufacturing process. In the
followings, description will solely be made with regard to an example
wherein only the carrier film is utilized as a manufacturing-process
material used for the information storing medium.

[0150]FIG. 7 is a schematic diagram showing a relation between the
encoded information 20 to be read by the reading unit 120 of the
continuous manufacturing system 1 and processed by an information
processing device 410, and the previously described control unit 400 for
controlling each of the units respectively provided in the optical-film
feed apparatus 100 (see FIG. 5) and the liquid-crystal-panel conveyance
apparatus 300 (see FIG. 5) for sequentially conveying the liquid-crystal
panels. The encoded information 20 recorded in the roll of the optical
film laminate 10 includes the slit-position information indicating the
positions at which respective ones of the slit lines are formed in pairs
in the continuous web of optical film, and optionally the identification
information for identifying the defective region over the normal region
of the polarizing composite film. Defects existing in the polarizing
composite film 11 included in the optical film are detected by the
inspection unit in the manufacturing process of the continuous web of
roll of optical film laminate 10, as described later, and based on
defective and normal regions in the polarizing composite film determined
from the locations or the coordinate positions of the detected defects,
at the slitting station of the continuous manufacturing system 1, the
slitting unit 150 forms a plurality of slits in the continuous web of the
optical film in a direction transverse to the feed direction of the
optical film sequentially fed, from the surface opposite to the carrier
film to a depth reaching the adhesive layer surface of the carrier film.

[0151] As shown in FIG. 7, the encoded information 20 is preferably
recorded on the carrier film contained in the optical film. The recorded
encoded information 20 is read by the reading unit including a code
reader or a CCD camera, and the encoded information 20 read in this
manner is transmitted to the information processing device 410 included
in the control unit 400 of the continuous manufacturing system 1. As is
clear from the control of each unit and the manufacturing process flow
illustrated in FIGS. 5 and 6, and the schematic diagram of FIG. 7, the
encoded information 20 read by the reading unit 120 is transmitted to the
information processing device 410, and then the information processing
device 410 functions to process the received encoded information 20. The
control unit 400 is also operable, based on the encoded information 20
processed by the information processing device 410, to systematically
control respective units included in the liquid-crystal-panel W
conveyance apparatus 300, and the optical-film feed apparatus 100, such
as the slitting unit 150 provided at the slitting station A, the
defective-polarizing-sheet removal unit 190 provided at the removal
station C and the lamination unit 200 provided at the lamination station
B, in an inter-related manner.

[0152] The outline of the control of the entire system will be described
below. Based on the slit-position information included in the processed
encoded information, the control unit 400 functions to control the
operation of the film feed unit 130 including the feed rollers to feed
the optical film and then control the operation of the first speed
adjustment unit 140 to temporarily stop the feed of the optical film.
Then, the control unit 400 functions to control the operation of the
slitting unit 150 at the slitting station A to form a plurality of slit
lines in the continuous web of the optical film in a direction transverse
to the feed direction of the continuous web of the optical film, from the
surface opposite to the carrier film to a depth reaching to the adhesive
layer surface of the carrier film.

[0153] The continuous web of the optical film having the slit lines formed
thereon is transported to the slitting position checkup unit 160 where
the slit line positions on the web are confirmed. Then, the defective
polarizing sheets Xβ and the normal polarizing sheets Xα
formed by the slit lines in the continuous web of the optical film are
identified or discriminated from each other based on the difference in
length, and only the defective polarizing sheets Xβ are peeled and
removed from the carrier film 14 using the defective-polarizing-sheet
removal unit 190 at the removal station C inter-related with the film
feed unit 170 including feed rollers and the speed adjustment unit 180.
In the case where encoded information includes the identification
information for identifying the defective region over the normal region,
it is possible for the defective-polarizing-sheet removal unit 190 to
peel and remove only the defective polarizing sheets Xβ from the
carrier film 14 based on the identification information. The continuous
web of the optical film from which the defective polarizing sheets
Xβ are removed is then transported by the carrier-film take up drive
mechanism 210 to the lamination station B, in synchronization with the
feed of the liquid-crystal panels being sequentially conveyed. The
carrier film 14 is taken up at a position where the leading edge of the
normal polarizing sheet Xα defined by the slit lines in the
polarizing composite film reaches the leading edge of the conveyed
liquid-crystal panel, where the normal polarizing sheet Xα is
peeled and the lamination unit 200 including the pair of lamination
rollers at the lamination station B starts laminating operation to attach
the normal polarizing sheet Xα to a corresponding one of the
liquid-crystal panels.

[0154] The manufacturing process of liquid-crystal display elements are
described with respect to specific operations of the respective units
operated by the control unit 400, including the laminating operation at
the lamination station B to attach the normal polarizing sheet Xα
to a corresponding one of the liquid-crystal panels.

(Removal of Defective Polarizing Sheet)

[0155] The defective-polarizing-sheet removal unit 190 is operated under
the control of the control unit 400 to identify or discriminate only the
defective polarizing sheet Xβ having a length different from that of
the normal polarizing sheet Xα, or only the defective polarizing
sheet Xβ associated with the identification information as a
defective polarizing sheet, from the carrier film 14 on which the normal
polarizing sheets Xα and the defective polarizing sheets Xβ of
the polarizing composite film 11 formed by the slit lines are laminated
in a releasable manner in the continuous web of the optical film, and
peel and remove only the defective polarizing sheet Xβ from the
carrier film 14. FIGS. 8 (1) and 8 (2) show such
defective-polarizing-sheet removal units 190 adapted, under control of
the control unit 400, to identify or discriminate only the defective
polarizing sheets Xβ.

[0156] The defective-polarizing-sheet removal unit 190 illustrated in FIG.
8 (1) comprises a dummy-film drive mechanism 191 having a function of
attaching to thereon and peeling the defective polarizing sheet from the
carrier film 14, and a move mechanism 192 adapted to be activated when
the defective polarizing sheet Xβ reaches a position in a feed path
where removal of the defective polarizing sheet is to be initiated,
wherein the move mechanism 192 is adapted to move the feed path of the
optical film so that the feed path of the optical film is moved toward
and away from the dummy-film feed path of the dummy-film drive mechanism
191.

[0157] The defective-polarizing-sheet removal unit 190 illustrated in FIG.
8 (2) is configured, at the lamination station B, under control of the
control unit 400, to be moved in an inter-related manner with the
lamination unit 200 including the pair of lamination rollers, and
comprises a dummy-film drive mechanism 191 having a function of attaching
to thereon and peeling the defective polarizing sheet Xβ from the
carrier film 14, and a movable roller 192 defining a dummy-film feed path
of the dummy-film drive mechanism 191. The removal unit illustrated in
FIG. 8 (2) is different from the removal unit illustrated in FIG. 8 (1)
in that, in the removal unit illustrated in FIG. 8 (2), at the lamination
station B, the movable roller 192 defining the dummy-film feed path is
disposed adjacent to the pair of lamination rollers of the lamination
unit 200, and adapted to be moved in an inter-related manner with the
lamination rollers of the lamination unit 200. More specifically, when
the defective polarizing sheet Xβ reaches the end position (i.e.,
the removal initiation position) of the feed path of the optical film at
the lamination station B, the pair of lamination rollers are moved apart
from each other, and the movable roller 192 defining the dummy-film feed
path is moved to a nip between the lamination rollers located in
spaced-apart relation, and moving the movable roller 192 and one of the
lamination roller in an inter-related manner by replacing the movable
roller 192 with the other of the lamination rollers. In this instance,
since the carrier film 14 is taken up by the carrier-film take up drive
mechanism 210, the defective polarizing sheet Xβ is peeled from the
carrier film 14, and the peeled defective polarizing sheet Xβ is
attached to the dummy-film feed path by means of the movable roller 192
operated in an inter-related manner with another roller of the pair of
the lamination roller and removed.

(Checkup of Slit Lines in the Continuous Web of the Optical Film)

[0158] In the manufacturing process of the continuous web of roll of the
optical film laminate 10, there are two regions previously defined,
comprising the defect-free normal region and the defective region having
a defect or defects, based on the locations or coordinate positions of
defects existing in the inspected polarizing composite film 11, and based
on such regions, the continuous web of the optical film unrolled from the
roll of the optical film laminate has the slit-position information which
is in the form of a coded information 20, the slit-position information
indicating the positions at which respective ones of the slit lines are
to be formed in the carrier film contained in the optical film being fed
during the manufacturing process of liquid-crystal display elements. The
slit-position information is read by the reading unit 120 in the
continuous manufacturing system 1 during the manufacturing process of
liquid-crystal display elements. Then at the slitting station A, the
slitting unit 150 functions, based on the read slit-position information,
to form the slit lines sequentially in the continuous web of the optical
film in the direction transverse to the feed direction. If the sequential
slit lines are not accurately formed, it will become meaningless to
control the operation of the slitting unit 150 in association with the
feed-length measurement data obtained from the optical film fed-out
distance measured during transportation of the optical film from the roll
of the optical film laminate 10.

[0159]FIG. 9 is a schematic diagram showing the operation of the slitting
position checkup unit 160 including the manner of inspection for
determining a difference between the position of a slit line actually
formed in the continuous web of optical film in the direction transverse
to its feed direction, and the slit line formation position at which the
slit-line is to be formed as read by the reading unit 120 in connection
with the feed-length measurement data of the optical film fed-out
distance. Two slitting position checkup units 160 are provided at the
upstream and downstream sides as seen in the feed direction of the
optical film with respect to the slitting unit 150. The film feed unit
170 including the feed rollers is disposed at the downstream side of the
downstream slitting position checkup unit 160, so that the downstream
slitting position checkup unit 160 functions to restart the feed of the
continuous web of optical film which is temporarily stopped when the slit
lines are formed. The speed adjustment unit 140 including the dancer
roller is disposed at the upstream side of the upstream slitting position
checkup unit 160, so that it is possible to maintain the feed of the
continuous web of optical film by the film feed unit 130 including the
feed rollers, even if the feed of the continuous web of optical film is
temporarily stopped when the slit lines are formed.

[0160] Coincidence of the position of the slit line actually formed in the
direction transverse to the feed direction of the continuous web of
optical film with the position obtained based on the feed-length
measurement data about the optical-film feed length can be affirmed by
determining the accurate positions in the traveling direction (X
direction) and the transverse direction (Y direction) of the optical
film. One preferable way is to carry out measurements, at two locations
at the opposite sides of the position of the optical film where the slit
line is to be formed, for the deviations in X and Y directions on the
position of the actually formed slit-line and the edge of the optical
film (the side end) with respect to respective reference lines. For
example, the slitting position checkup unit 160 may be provided with a
CCD camera to take images of the position of the actually formed
slit-line and the position of the edge of the optical film, and produce
picturized images. The reference lines are previously provided in the
image-taking regions. The position of the actually formed slit-line and
the position of the edge of the optical film can be determined in terms
of differences in contrasts in the taken images. Then, a calculation is
made to determine the distance (deviation) between the predetermined
reference lines and the positions of the actually formed slit-line and
the edge of the optical film, and the location and the angular position
of the slitting unit 150 is corrected forwardly or backwardly with
respect to the feed direction of the continuous web of optical film,
based on the calculated distance (deviation).

[0161] More specifically, as shown in FIG. 6, Steps 3, 4 and 7 are
performed to feed the continuous web of the optical film under tension,
and in Step 5, a slit line is formed in the continuous web of the optical
film. Then, a further step is carried out by the two slitting position
checkup units 160 to determine whether there is any deviation between the
position of the actually formed slit-line of the optical film and the
position where the slit-line is to be formed, the latter position being
determined based on the slit-position information read by the reading
unit 120, and in the case where there is any deviation, Steps 6 and 8 are
carried out, for example, in the following manner.

[0162] The manner of the inspection for determining the deviation between
the position of the actually formed slit-line of the continuous web of
optical film and the position where the slit-line is to be formed as read
by the reading unit 120 is carried out for example in accordance with the
following procedures.

[0163] (1) Images of the position (X) of the actually formed slit line of
the optical film and two positions (Y1, Y2) of the edge of the optical
film are taken by the CCD camera of the slitting position checkup unit
160, and the images are picturized for measurement of the position of the
actually formed slit-line (X) of the optical film and the positions of
the edges (Y1, Y2) of the optical film by the differences in contrast.

[0164] (2) There is a slit line reference position in the form of a line
extending in Y direction at a position intermediate between a reference
line extending in Y direction at an upstream position as seen in X
direction in the imaging area of one of the slitting position checkup
units 160 and another reference line extending in Y direction at a
downstream position as seen in X direction in the imaging area of the
other of the slitting position checkup units 160, and data γ
representing the distance between the upstream and downstream reference
lines is stored in the storage device 420 via the information processing
device 410. Furthermore, there are upstream and downstream reference
lines extending in the X direction in respective ones of the image-taking
regions of the slitting position checkup units 160.

[0165] (3) A correction value α for the position of the slit-line
and a correction value δ for the angular position of the slit-line
are calculated based on the reference lines and the measured positions of
the slit-line (X) and the edge of the optical film. The correction value
α for the position of the slit-line in the optical film correspond
to the measured deviation α, or the deviation α between the
actual slit-line position (X) and the downstream side reference line
extending in the Y direction. The correction value δ for the
angular position of the slit line can be calculated according to the
following formula, based on the deviations in Y direction of the edge of
the optical film at two positions, or the deviations (β1, β2)
of the edge of the optical film with respect to respective ones of the
upstream and downstream reference lines extending in the X direction, and
the distance data γ between the two reference lines.

δ = cos - 1 { γ γ 2 + ( β 1
- β 2 ) 2 } [ Equation 1 ] ##EQU00001##

[0166] (4) The storage device 420 is used to store correction values
(α, δ) for applying an instruction to the slitting unit 150
to perform an angular position correction by a value δ and a
positional correction by value α in the X direction based on the
measured and calculated data so as to make the slit line conform to the
reference slit-line position extending in the Y direction.

[0167] (5) The slitting unit 150 receives instruction from the control
unit 400 for the next operation of forming a slit line in the optical
film to perform a positional correction in the feed direction and an
angular position correction in a crosswise direction with respect to the
feed direction, based on the stored correction values (α, δ).

[0168] (6) Thereafter, the slitting unit 150 forms a next slit line in the
continuous web of optical film.

[0169] The first feature concerning the roll of optical film laminate 10
according to this embodiment is that, in advance of laminating the normal
polarizing sheet X.sub.α cut from the polarizing composite film 11
contained in the continuous web of optical film being supplied on the
liquid-crystal panel W, only the defective polarizing sheets X.sub.β
cut from the polarizing composite film 11 taken away by the
defective-polarizing-sheet removal unit 190, without interrupting the
feed of the optical film. The second feature of this embodiment is that
only the normal polarizing sheet Xα cut from the polarizing
composite film 11 can be fed to the lamination unit 200 for lamination
with respective ones of the liquid-crystal panel W at the lamination
station B by the carrier-film take up drive mechanism 210, while
eliminating a need for interrupting the feed of the optical film. The
above features are inconceivable in the case of an individualized sheet
or in the manufacture of individualized sheets. It is apparent that the
uses of such roll of the optical film laminate 10 in the manufacturing
process of the liquid-crystal display element leads to a significant
increase in the speed and a significant improvement in accuracy of
applying the normal polarizing sheet X.sub.α to the liquid-crystal
panel W

[0170] Before specifically describing in detail the lamination unit 200
including the pair of lamination rollers adapted to be vertically moved
toward and away from each other for laminating the liquid-crystal panel W
with the normal polarizing sheet Xα which has been cut from the
polarizing composite film 11, a brief description is made regarding the
transportation or liquid-crystal-panel conveyance apparatus 300 for the
liquid-crystal panel W which is to be laminated with the normal
polarizing sheet of the polarizing composite film 11 formed from the
continuous web of the optical film which is also being supplied.

[0171] Taking a large size television having a diagonal screen dimension
of 42 inches as an example, a rectangular-shaped liquid-crystal panel W
has a size of about 540 to 560 mm in length and about 950 to 970 mm in
width. During the manufacturing process of liquid-crystal display
elements, the liquid-crystal panel W is slightly trimmed along its
peripheries during a wiring stage including mounting operations of
electronic components. Alternatively, the liquid-crystal panel W may be
transported or conveyed with peripheries already trimmed. The
liquid-crystal panels W are taken out one-by-one from a magazine
containing a large number of liquid-crystal panels, by means of a
liquid-crystal-panel supply apparatus, and as shown in FIG. 6 and FIG.
10, conveyed through cleaning/polishing stage to the lamination unit 200
at the lamination station B for lamination with respective ones of the
normal polarizing sheet, by the liquid-crystal-panel conveyance apparatus
300, by being adjusted to equal intervals and a constant transportation
speed, for example. The normal polarizing sheet Xα is formed from
the continuous web of optical film to have a size slightly less than that
of the liquid-crystal panel W. As shown in FIG. 10, in synchronization
with the transportation of the normal polarizing sheet Xα when the
normal polarizing sheet Xα is transported to the lamination station
B, in a final stage of the liquid-crystal panel W sequentially conveyed
to the lamination station B for lamination of the normal polarizing sheet
Xα on the liquid-crystal panel W, the liquid-crystal-panel
conveyance apparatus 300 includes a liquid-crystal panel orientation
controlling unit comprising a pre-alignment unit 310 and a
final-alignment unit 320 for controlling the orientation of the
liquid-crystal panel W, a conveyance unit 330 to transport the panel to
the lamination position, and a panel-edge detection unit 340 for
detecting the leading edge of the liquid-crystal panel W.

[0172] FIG. 10 is a schematic diagram showing the transportation of the
liquid-crystal panels W in an aligned orientation, by means of the
pre-alignment unit 310, the final-alignment unit 320, the conveyance unit
330 for conveying the panels to the lamination position, and the
panel-edge detection unit 340 which are provided in the
liquid-crystal-panel conveyance apparatus 300, based on the encoded
information 20 which is read from the continuous web of optical film by
the reading unit 120 during the manufacturing process of liquid-crystal
display elements. Further, FIG. 11 is a schematic diagram showing the
lamination unit 200 for laminating the polarizing composite film sheet
with the liquid-crystal panel W, comprising the sheet-edge detection unit
220 for detecting the leading edge of the normal polarizing sheet
Xα formed from the continuous web of the optical film being fed,
and the straight-ahead-posture detection unit 230 for detecting the
alignment with the feed direction of the normal polarizing sheet
Xα, and a peeling plate 211 for peeling the carrier film 14 by
being bent at an acute angle from the normal polarizing sheet Xα.

[0173] Preferably, the normal polarizing sheet Xα is fed to the
lamination unit 200 at the lamination station B at a constant speed by
the carrier film 14. As shown in FIG. 10 or 11, at the lamination station
B, only the carrier film 14 is peeled by being bent at an acute angle,
via the peeling plate 211, by the carrier-film take up drive mechanism
210. By having the carrier film 14 peeled by being bent at an acute
angle, the adhesive layer on the normal polarizing sheet Xα may be
gradually exposed. This makes it possible to slightly expose the leading
edge of the normal polarizing sheet Xα to allow the leading edge of
the liquid-crystal panel W to be easily aligned with the leading edge of
the normal polarizing sheet Xα.

[0174] As shown in FIG. 10, the leading edge of the normal polarizing
sheet Xα is moved to the nip defined between the pair of lamination
rollers of the lamination unit 200 which are now in the vertically spaced
apart relation to each other, and detected by the sheet-edge detection
unit 220. Although the normal polarizing sheet Xα is fed in a state
laminated on the carrier film 14, it is seldom that the normal polarizing
sheet Xα is accurately fed so that the angle θ between the
feed direction and the lengthwise direction of the carrier film 14
becomes zero. Therefore, deviations of the normal polarizing sheet
Xα in the feed direction and the transverse direction are measured,
for example, by taking images of the sheet using the CCD camera of the
straight-ahead-posture detection unit 230 and subjecting the taken images
to an image processing, whereby the measured deviations are calculated in
terms of x, y and θ, and the calculated data is stored in the
storage device 420 by the control unit 400.

[0175] Then, a plurality of liquid-crystal panels W are sequentially
supplied from a transportation unit including a magazine containing a
plurality of the liquid-crystal-panels illustrated in FIG. 5 at even
intervals and a constant speed, furthermore, the liquid-crystal panels W
are supplied one-by-one and subjected to the alignment control by the
liquid-crystal-panel conveyance apparatus 300 illustrated in FIG. 10.
This alignment control are described with reference to FIG. 10.

[0176] The liquid-crystal panels W are sequentially positioned by the
pre-alignment unit 310, so that they are aligned in lengthwise and
widthwise directions respectively with the transport direction and the
direction perpendicular to the transport direction in the conveyance
path. The positioned liquid-crystal panel W is conveyed to and placed on
the final-alignment unit 320 which includes an alignment table adapted to
be turned by a drive mechanism which is controlled by the control unit
400. The leading edge of the liquid-crystal panel W placed on the
alignment table is detected by the panel-edge detection unit 340. The
position of the detected leading edge of the liquid-crystal panel W is
checked for match with the reference lamination position stored in the
storage device, specifically, the calculation data in terms of x, y and
θ to represent the orientation of the normal polarizing sheet
Xα to be laminated to the liquid-crystal panel W. For example, the
deviation between the leading edge of the liquid-crystal panel W and the
reference lamination position is measured using an alignment mark of the
liquid-crystal panel W illustrated in FIG. 2 to calculate the angular
displacement θ, and the alignment table 321 having the
liquid-crystal panel W placed thereon is turned by the angular
displacement θ. Then, the alignment table 321 is connected to the
conveyance unit 330 directed for the lamination station B. The
liquid-crystal panel W is conveyed to the lamination position while
keeping the same orientation, by the conveyance unit 330 directed for the
lamination station B, and the leading edge of the liquid-crystal panel W
is registered with and laid on the leading edge of the normal polarizing
sheet Xα. In the final stage, the normal polarizing sheet Xα
and the liquid-crystal panel W which are in aligned relation with each
other are held between the pair of lamination rollers and conveyed
thereby to obtain a finished liquid-crystal display element.

[0177] The normal polarizing sheet Xα is fed to the lamination unit
200 for lamination with the liquid-crystal panel W together with the
carrier film 14 within the continuous web of optical film advanced under
tension, so that there is least possibility that the periphery of the
normal polarizing sheet Xα is bent or sagged. Thus, the normal
polarizing sheet Xα is less likely be flexed or bent. This makes it
easy to have orientation of the liquid-crystal panel W aligned with the
normal polarizing sheet Xα which is fed to the lamination station
B, so that the manufacturing speed of the liquid-crystal display element
can be increased and the product accuracy can be improved. Such method
and system can never be applied to the manufacturing process utilizing
individualized sheets wherein, after peeling a separator from each of the
individualized sheets to expose the adhesive layer, and feeding under a
vacuum suction each of the sheets to a lamination position, adjusting the
position of the sheet with respect to the liquid-crystal panel W, the
sheet is laminated to the liquid-crystal panel W to complete a
liquid-crystal display element. Thus, this embodiment is a continuous
manufacturing method and system for liquid-crystal display elements based
on the features of providing and using a roll of a continuous web of an
optical film 10 having a width corresponding to the width of a
liquid-crystal panel having predefined dimensions and at least comprising
a polarizing composite film 11 having an adhesive layer 12 provided
thereon and a carrier film 14 releasably attached to the adhesive layer
12, the continuous web of optical film 10 having a plurality of
defective-polarizing-sheet slitting positions and normal-polarizing-sheet
slitting positions defined thereon as lines extending in the widthwise
direction of the continuous web of optical film, based on positions of
one or more defects existing in the continuous web of optical film
detected through a preliminary inspection of a polarizing composite film
11, the defective-polarizing-sheet slitting positions defining regions
having one or more defects and the normal-polarizing-sheet slitting
positions defining regions having no defect, information for the slitting
positions relating to the defective-polarizing-sheet slitting positions
and normal-polarizing-sheet slitting positions being recorded as encoded
information 20.

[0178] II. Roll of Optical Film Laminate, Manufacturing Method and System
Therefor

[0179] Below is a description of the roll of the optical film laminate, a
manufacturing method and system therefore according to at least one
disclosed embodiment with reference to the drawings.

(Structure of Polarizing Composite Film)

[0180] As shown in FIG. 1A and FIG. 1B, the sheet of the optical film to
be laminated to the liquid-crystal panel is typically comprised of a
flexible optical film including a polarizing composite film formed with
an acrylic adhesive layer for lamination with a glass substrate of the
liquid-crystal panel W. The polarizing composite film includes a
polarizer (continuous polarizer layer) having a thickness of 20 to 30
μm comprising a substrate made of a PVA-based film which has been
subjected to a dyeing treatment using iodine and a cross-linking
treatment, and thereafter subjected to an orienting treatment by a
lengthwise or widthwise stretching, and the polarizer is provided on one
or each surface with a transparent protective film which is laminated
thereon and comprises a substrate of TAC-based film having a thickness of
about 40 to 80 μm for protecting the polarizer. Typically, an acrylic
adhesive layer is formed on the surface of the polarizer for lamination
with the liquid-crystal panel W

(Process Using Conventional Individualized Sheets)

[0181] As already described, in an individualized sheet manufacturing
process, individualized sheets are prepared by punching or cutting a
continuous web of optical film into pieces of rectangular shape, each
being laminated with a separator through an adhesive layer. The
individualized sheets each formed into a rectangular shape and laminated
with the separator are previously stored in a magazine in a
liquid-crystal display element manufacturing line. Then, in a process of
laminating the individualized sheets with respective ones of a plurality
of liquid-crystal panels W, the individualized sheets stored in the
magazine are conveyed under suction to a lamination position one-by-one.
The separator releasably laminated to the adhesive layer formed on each
of the individualized sheets is peeled to expose the adhesive layer, and
the individualized sheet is laminated to a corresponding one of the
liquid-crystal panels W through the exposed adhesive layer. During this
process, since the individualized sheet is flexible, problems are
experienced in that the periphery of the rectangular-shaped
individualized sheet is bowed or warped. Thus, in a liquid-crystal
display element manufacturing process using such individualized sheet, in
order to quickly perform alignment and lamination with a liquid-crystal
panel with a high degree of accuracy, there is no other choice but to use
individualized sheets which may have less problem of bowing or warping.
For the purpose, for example, protective films each having a thickness of
40 to 80 μm are laminated to both of the opposite surfaces of a
polarizer, but not to one of the surfaces, to impart stiffness to the
individualized sheet by increasing thickness.

(Method and System for Manufacturing Roll of Optical Film Laminate)

[0182] FIGS. 12 to 14 are schematic diagrams showing methods and systems
for manufacturing rolls of the optical film laminate including a
polarizing composite film, used for the present disclosure. FIGS. 15 to
17 are flowcharts showing respective manufacturing processes or
manufacturing steps in the manufacturing methods and systems according
the disclosed embodiments.

[0183] In the disclosed embodiments, the polarizing composite film 11
constituting the roll of the optical film laminate 10 may be made of a
polarizer including a substrate of a PVA based material having at least
one surface laminated with a protective film, preferably of a transparent
material, with an adhesive layer 12 provided on the other surface. A
carrier film 14 adopted as a manufacturing-process material is releasably
attached to the adhesive layer 12. In the conventional manufacturing
process of liquid-crystal display elements using individualized sheets,
the polarizing composite film used therein has two protective films
laminated thereon at the opposite surfaces to impart stiffness to the
polarizing sheet. However, in a liquid-crystal display element
manufacturing process using the roll of the optical film laminate in
accordance with at least one embodiment, the normal polarizing sheet
Xα formed from the polarizing composite film 11 in the roll of the
optical film laminate 10 is peeled from the carrier sheet 14 at the
lamination position, and will gradually be separated from the web. It is
to be understood as a matter of course that there is no need of peeling
the separator on a piece-by-piece basis as in the manufacturing process
using the individualized sheets.

[0184] When the normal polarizing sheet Xα is peeled from the
carrier film 14, the leading edge of the normal polarizing sheet Xα
is registered with the leading edge of a corresponding one of a plurality
of liquid-crystal panels W being sequentially conveyed one-by-one toward
the lamination position and then, the normal polarizing sheet Xα
and the corresponding liquid-crystal panel W are laminated together by
being pressed against each other by the pair of lamination rollers of the
lamination unit 200 at the lamination station B. In this process, there
is no risk that the periphery of the normal polarizing sheet Xα is
bowed or warped since the sheet gradually comes out. Thus, differently
from the individualized sheet, in the polarizing composite film 11
included the optical film in the disclosed embodiments, the protective
film may be laminated to only one of the surfaces of the polarizer, and
additionally it is possible to make the thickness of the protective film
to be 40 μm or less.

[0185] Below is a description of the manufacturing methods and systems of
the roll of the optical-film laminate, according to the disclosed
embodiments, taking reference to FIGS. 12 and 15, FIGS. 13 and 16, and
FIGS. 14 and 17, respectively.

(Method and System for Manufacturing Roll of Optical Film Laminate
According to the Embodiment Illustrated in FIG. 12)

[0186] FIG. 12 is a schematic diagram showing the manufacturing system 500
for manufacturing the roll of the optical film laminate which comprises a
polarizer manufacturing line 510 for producing a continuous polarizer
layer (hereinafter referred to as "polarizer" as in the previous
description), a protective film manufacturing line 520 for producing a
protective film to be laminated on the polarizer, a lamination line or
provisional-optical-film feed line 530 for producing a laminate
consisting of the polarizer and the protective film (the laminate will
hereinafter be referred to as "polarizing sheet 11'" to distinguish it
from the polarizing composite film 11 which does not have an adhesive
layer), and surface-protection film lamination mechanism 640 and
carrier-film lamination mechanism 570 for laminating a carrier film and a
surface-protection film, to the polarizing composite film to produce the
optical film. FIG. 15 is a flowchart showing the manufacturing process or
steps in the system 500.

[0187] The lamination line or provisional-optical-film feed line 530
includes an inspection sub-line for inspecting a defect existing in the
polarizing sheet 11' by an inspection unit 560, a carrier film feed
sub-line for laminating a carrier film 14 having a transferable adhesive
layer 12 formed thereon, to one of the opposite surfaces of the
polarizing sheet 11', an information recording sub-line for recording
encoded information including slit-position information, on a surface of
the carrier film 14, a surface-protection film feed sub-line for
laminating a surface protection film 13 through an adhesive surface to
the surface of the polarizing sheet 11' opposite to the surface on which
the carrier film 14 is laminated, and a taking up sub-line for taking up
the continuous web of optical film having the encoded information
recorded thereon to form a roll of the optical film. The carrier film
feed sub-line has mounted thereon a roll of the carrier film 14 having a
releasing film attached thereto, and the surface-protection-film feed
sub-line has mounted thereon a roll of the surface protection film 13
having a releasing film attached thereto at its adhesive surface. The
slit-position information is obtained by processing the information about
a normal region (region having no defect) and a defective region (region
having a defect or defects) which are previously defined in the
polarizing sheet 11' based on the location or coordinate position of the
defect therein detected at the inspection sub-line, and used to, in
forming a normal polarizing sheet and a defective polarizing sheet
comprising an adhesive layer, designate at least positions at which slit
lines are to be formed in the continuous web of optical film being fed.

[0188] The polarizer manufacturing line 510 has a roll of PVA-based film
which constitute the substrate of the polarizer and is mounted thereon in
a rotatable manner, and includes a sub-line for subjecting the PVA-based
film being unrolled from the roll by means of a lamination drive
mechanism 540 or other drive mechanism (not shown), to processes of
dyeing, cross-linking, stretching and then drying. The protective film
manufacturing line 520 has rotatably mounted thereon a roll of a
typically transparent TAC-based film constituting a substrate of the
protective film, and includes a sub-line for subjecting the transparent
TAC-based film being unrolled from the roll by means of the lamination
drive mechanism 540 or other drive mechanism (not shown), to a
saponifying treatment followed by drying. Each of the protective film
manufacturing line 520 and the polarizing sheet 11' lamination line or
provisional-optical-film feed line 530 includes a sub-line for applying
an adhesive consisting primarily of a polyvinyl alcohol-based resin to an
interface between the polarizer and the protective film, and drying the
adhesive to bond them together through an adhesive layer having a
thickness of only several μm.

[0189] The lamination line or provisional-optical-film feed line 530 for
the polarizing sheet 11' comprises the lamination drive mechanism 540
including a pair of lamination rollers. The lamination drive mechanism
540 comprises a length or distance measurement device 550 having an
encoder incorporated in one of the lamination rollers for calculating the
length fed from the leading edge of the formed polarizing sheet 11'. The
lamination rollers are adapted to laminate the protective film to the
polarizer by pressing them against each other, to form a polarizing sheet
11', and feed the polarizing sheet 11'.

[0190] This manufacturing system 500 includes the inspection unit 560 for
detecting defects in the surface and the inside of the polarizing sheet
11'. It is required to provide the polarizing sheet 11' with the adhesive
layer 12 only after the defects are detected, to complete the polarizing
composite film 11. Therefore, the present manufacturing system 500
further comprises a carrier-film supply mechanism 570 having mounted
thereon the roll of the carrier film 14 having the adhesive layer 12. The
adhesive layer 12 on the carrier film 14 is formed in advance in the
manufacturing process of the carrier film 14, by subjecting one of the
opposite surfaces of the carrier film 14 which is to be releasably
laminated to one of the opposite surfaces of the polarizing sheet 11' to
be laminated to the liquid-crystal panel W to a releasing treatment, and
then applying to that surface a solvent containing an adhesive drying the
solvent. When the carrier film 14 fed from the carrier-film supply
mechanism 570 is laminated on the polarizing sheet 11' in a releasable
manner, the adhesive layer 12 previously formed on the carrier film14 is
transferred to the polarizing sheet 11' to provide the adhesive layer 12
on the polarizing composite film 11.

[0191] The present manufacturing system 500 further comprises an
information recording unit 630 for recording encoded information, for
example, on a surface of the carrier film 14. More specifically, the
information recording unit 630 is operable to record, on a continuous web
of optical film being fed during the liquid-crystal display element
manufacturing process using the produced roll of the optical-film
laminate, encoded information including the slit-position information
indicative of the positions at which slit lines are to be formed in the
continuous web of optical film to form normal polarizing sheets and
defective polarizing sheets having the adhesive layer. The manufacturing
system 500 may further comprise a surface-protection-film lamination
mechanism 640 for laminating a surface-protection film 13 through an
adhesive surface to the surface of the polarizing sheet 11' opposite to
the surface on which the carrier film 14 is laminated. Finally, the
manufacturing system 500 comprises an optical-film take up drive
mechanism 580 for drivingly taking up the optical film which is
constituted by the polarizing sheet 11' with the carrier film 14 having a
transferable adhesive layer and the surface-protection film 13 laminated
on the opposite surfaces of the polarizing sheet 11'.

[0192] In the case where protective films are laminated on the opposite
surfaces of the polarizer, the present manufacturing system 500 will
include two protective film manufacturing lines 520, 520' (the protective
film manufacturing line 520' is omitted in the drawing). Further, the
protective film manufacturing line 520 may additionally include a
treatment sub-line for, before a protective film is laminated to the
polarizer, subjecting the surface of the protective film to a hard coat
treatment and/or an anti-dazzling or anti-glare treatment.

[0193] The inspection unit 560 comprises an image-reading device 590
including for example a CCD camera. The image-reading device 590 is
electrically connected to an information processing device 610 included
in a control unit 600, wherein image data read by the image-reading
device 590 is processed in association with feed-length measurement data
measured by the length or distance measurement device 550 electrically
connected to the information processing device 610. The control unit 600
functions to operate the information processing device 610 and a storage
device 620 to process the image data from the image-reading device 590 in
association with the feed-length measurement data based on the delivered
length measured by the length or distance measurement device 550 as a
length from the leading edge of the polarizing sheet 11', so as to
produce position data representing locations or coordinate positions of a
defect or defects in the polarizing sheet 11', the position data being
then stored in the storage device 620. The control unit 600 functions,
based on the position data on the detected locations or coordinate
positions of a defect or defects, to define defective regions and normal
regions in the polarizing composite film 11.

[0194] The control unit 600 functions, based on the position data on the
detected locations or coordinate positions of a defect or defects, to
define defective regions and normal regions in the polarizing composite
film 11. Further, the control unit 600 functions, based on the defective
and normal regions of the polarizing composite film 11, to create
slit-position information. The slit-position information is provided for
indicating positions at which respective ones of the slit lines are to be
formed in the continuous web of optical film, furthermore, the slit lines
are formed in pairs by the slitting unit 150 during the manufacturing
process of the liquid-crystal display elements, in a manner as to slit
the continuous web of optical film being fed in a direction transverse to
the feed direction of the continuous web, from the surface opposite to
the carrier film to a depth reaching the adhesive layer surface of the
carrier film. The produced slit-position information is also stored in
the storage device 620. Then, the information processing device 610
functions, based on the stored slit-position information, to create
encoded information, together with additional information, such as
information on the manufacturing lot and a length in meters of the
optical film in the roll, or in association with the additional
information. As already mentioned, the encoded information is preferably
recorded on the carrier film 14 included in the continuous web of optical
film, during the manufacturing process of liquid-crystal display elements
using the roll of the optical film laminate. It is to be understood that
the manner of recording the encoded information on the carrier film 14
can vary in various ways, such as the one in which encoded information is
entirely recorded on a single storage location, and the one in which
encoded information is recorded on a plurality of storage areas disposed
at given intervals (e.g., at intervals of 1 m or 100 m). Alternatively,
the encoded information may be recorded on the surface-protection film
13, if any, instead of the carrier film 14.

[0195] It is to be noted that the regions defined by respective pairs of
slit lines may include defect-free normal regions having a given length
determined by the length of a side of the liquid-crystal panel to be
laminated with the polarizing composite film, or defective regions having
a length usually less than the given length. During the manufacturing
process of the liquid-crystal display element, it is necessary to allow
the slitting unit 150 to cut defective regions and normal regions of the
polarizing composite film 11 along corresponding ones of the pairs of
slit lines based on the slit-position information included in the encoded
information, so that the formed defective polarizing sheets Xβ are
removed from the carrier film 14 by the defective-polarizing-sheet
removal unit 190, and the similarly formed normal polarizing sheets
Xα are peeled from the carrier film 14 to be laminated to one
surface of the liquid-crystal panels W.

[0196] Therefore, the length (Xα) of the normal region is determined
based on the position data relating to the location or coordinate
position of the defect existing in the polarizing composite film 11 in
accordance with the length of a side of the liquid-crystal panel to be
laminated with the normal polarizing sheet, so that the length always has
a constant value. Regarding the defective region which is defined in the
same manner, however, the upstream one of the two slit lines for the
normal region located just upstream of the defective region in a feed
direction can be used as the downstream one of the two slit lines for the
defective region, so that the length (Xβ) of the defective region is
determined by the downstream slit line and an upstream one which is
located slightly upstream of the location or coordinate position of the
defect. Since the length between the downstream slit line and the
location or coordinate position of a defect may not be the same, the
length (Xβ) of the defective region varies. Preferably, a
calculation algorithm for producing the slit-position information
indicating the positions for forming the slit lines is configured such
that the length (Xβ) of the defective region is different from the
length (Xα) of the normal region, for example, to have a relation
Xβ<Xα, in any case, as described later. The procedure of
creating the encoded information is common in the disclosed embodiments,
so that the procedure will be described later in connection with
reference to FIG. 18 and FIGS. 19 to 21.

[0197] The carrier-film lamination mechanism 570 for laminating the
carrier film 14 to the polarizing sheet 11' is be described below. The
carrier film 14 is previously formed in the carrier film manufacturing
line (not shown) using a PET (polyethylene terephthalate)-based film of
about 20 to 40 μm in thickness as a substrate. A transferable adhesive
layer having a thickness of about 10 to 30 μm can be formed on one of
the opposite surfaces of the carrier film 14 by, after subjecting one of
the opposite surfaces of the PET-based film to a releasing treatment,
applying a solvent containing an acrylic adhesive to the treated surface,
and drying the solvent. By having the carrier film 14 laminated in a
releasable manner on the polarizing sheet 11', the adhesive layer is
transferred to the polarizing sheet 11' to form the optical film which
comprises the polarizing composite film 11 having the adhesive layer12.
During the manufacturing process of liquid-crystal display elements using
the roll of the optical film laminate 10 formed in the above described
manner, the adhesive layer 12 is peeled together with the normal
polarizing sheet from the carrier film 14 when the normal polarizing
sheet is peeled from the carrier film 14 and attached to the
liquid-crystal panel W. The carrier film 14 previously produced in the
carrier film manufacturing line is wound into a roll by a length
corresponding to the wound length of the polarizing composite film 11.

[0198] In a process of producing a roll of a provisional optical film
laminate in accordance with the embodiments illustrated in FIGS. 13 & 14,
a transferable adhesive layer may be formed on the provisional optical
film in the same manner. In the embodiments illustrated in FIGS. 13 & 14,
when a provisional carrier film and/or a provisional surface-protection
film are peeled, the adhesive layer formed on the provisional carrier
film is transferred to the polarizing composite film 11, so that the
adhesive layer 12 may be formed on one of the opposite surfaces of the
polarizing composite film 11, in the same manner, as described later.

[0199] The roll of the carrier film 14 is mounted for rotation on a
support rack 571, and the carrier film 14 unrolled from the roll is
releasably laminated on the polarizing sheet 11' by the carrier-film
lamination mechanism 570. A releasable-film take up drive mechanism 572
is provided to function, when the carrier film 14 is releasably laminated
on the polarizing sheet 11', to take up a releasable film provided for
protecting the adhesive layer formed on the carrier film 14 and to expose
the adhesive layer.

[0200] Referring to the flowchart of FIG. 15, in Step 1, the lamination
drive mechanism 540 functions to laminate the protective film to one
surface of the polarizer to thereby produce the polarizing film 110 which
is then fed while being produced. In Step 2, defects existing in the
polarizing sheet 11' thus produced and being fed are detected by the
inspection unit 560. In Step 3, the roll of the carrier film 14 is
rotatably mounted on the support rack 571. In Step 4, the releasable-film
take up drive mechanism 572 and the optical-film take up drive mechanism
580 functions to unroll the carrier film 14 formed with the transferable
adhesive layer from the roll with the adhesive layer in exposed state. In
Step 5, the carrier film 14 is releasably laminated on the polarizing
sheet 11' through the adhesive layer by the carrier-film lamination
mechanism 570, to form the polarizing composite film 11 having the
adhesive layer 12.

[0201] The information processing device 610 functions to define defective
and normal regions in the polarizing composite film 11 based on the
locations or coordinate positions of the defects detected in Step 2, and
then, based on the defined defective and normal regions, creates
slit-position information for forming defective polarizing sheets Xβ
and normal polarizing sheets Xα in the polarizing composite film
11. In Step 6, the created slit-position information is recorded on a
surface of the carrier film 14 laminated on the polarizing composite film
11, by the information recording unit 630. Finally, in Step 7, an optical
film formed through the above Steps is taken up by the optical-film take
up drive mechanism 580, to form a roll of the optical film laminate.

[0202] Although the descriptions have been made herein with respect to a
process wherein the step of forming the adhesive layer 12 on the
polarizing composite film 11, simultaneously with the step of releasably
laminating the carrier film 14 on the adhesive layer 12, it is to be
understood that the adhesive layer 12 may be previously formed on the
polarizing composite film 11. Further, in advance of Step 7, the adhesive
surface of the surface-protection film 13 may be additionally laminated
on the surface of the polarizing composite film 11 opposite to the
surface on which the carrier film 14 is laminated by means of the
surface-protection-film lamination mechanism 640, irrespective of whether
the protective film is subjected to the hard coating treatment or the
anti-dazzling or anti-glare treatment, before the protective film is
laminated to the polarizer. In this case, the resulting optical film has
a structure having the carrier film 14 and the surface-protection film 13
laminated on respective ones of the opposite surfaces of the polarizing
composite film 11.

(Method and System for Manufacturing a Roll of Optical Film Laminate
According to the Embodiment Illustrated in FIG. 13)

[0203]FIG. 13 is a schematic diagram showing the manufacturing system of
the roll of the optical film laminate, wherein a roll of a provisional
optical film laminate 10' is mounted on a support rack, the roll
comprising a polarizing composite film 11 including a polarizer laminated
with a protective film, and a provisional carrier film 14' releasably
laminated on the polarizing composite film 11 through an adhesive layer,
and wherein a continuous web of the provisional optical film is
continuously unrolled and the provisional carrier film 14' is peeled from
the continuous web of the provisional optical film to be subjected to an
inspection for detecting defects existing in the polarizing composite
film 11 with the adhesive layer 12 in an exposed state, a carrier film 14
being thereafter laminated in a releasable manner on the adhesive layer
12 of the polarizing composite film 11, the slit-position information
being recorded on a surface of the carrier film 14 in the same manner as
in the embodiment illustrated in FIG. 12, to produce a roll of the
optical film laminate 10. FIG. 16 is a flowchart showing the
manufacturing process or steps in the system.

[0204] In the process of producing the roll of a provisional optical film
laminate 10', a transferable adhesive layer is first formed on the
provisional carrier film 14'. Thus, when the provisional carrier film 14'
is peeled from the continuous web of the provisional optical film being
continuously drawn from the roll, the adhesive layer12 formed on the
provisional carrier film is transferred to the polarizing composite film
so as to be incorporated into the polarizing composite film 11. In place
of the provisional carrier film 14' formed with the transferable adhesive
layer, an adhesive layer 12 may be first formed on the polarizing
composite film, and then a provisional carrier film 14'' formed as a
simple film subjected to a releasing treatment may be laminated to the
adhesive layer 12. Further, a surface of the protective film to be
laminated to the polarizer may be subjected to a hard coating treatment
or an anti-dazzling or anti-glare treatment.

[0205] The manufacturing system 500 for a roll of the optical film
laminate 10 according to the embodiment illustrated in FIG. 13 comprises
the following elements in common with the manufacturing system according
to the embodiment illustrated in FIG. 12; the inspection unit 560
including the image-reading device 590 for detecting a defect or defects
existing in the polarizing composite film 11 including an adhesive layer
12; the carrier-film lamination mechanism 570 including the support rack
571 having the roll of the carrier film 14 mounted thereon for rotation;
the optical-film take up drive mechanism 580 for driving and taking up
the produced optical film into a roll; the control unit 600 including the
information processing device 610 for performing an information
processing and the storage device 620 for storing therein processed
information; and the information recording unit 630 for recording
produced encoded information on the optical film (final optical film).
The manufacturing system 500 further comprises a lamination line or
provisional-optical-film feed line 530 including a support rack 531
having a roll of the provisional optical film laminate 10' mounted
thereon for rotation, and a lamination drive mechanism 540 including a
pair of feeding drive rollers for continuously feeding the provisional
optical film. The lamination drive mechanism 540 includes a length or
distance measurement device 550 having an encoder incorporated in one of
the feeding drive rollers to calculate a length fed from the leading edge
of the provisional optical film. Additionally, the manufacturing system
500 comprises a provisional-carrier-film peeling unit 575 including a
provisional-carrier-film take up drive mechanism 576.

[0206] Referring to the manufacturing process illustrated in FIG. 16, in
Step 1, the roll of the provisional optical film laminate 10' is mounted
in the support rack 531. The provisional optical film comprises a
polarizing composite film 11 including a polarizer having a protective
film laminated to one or each of opposite surfaces of the polarizer, and
a provisional carrier film 14' formed with a transferable adhesive layer
and laminated to the polarizing composite film 11. In Step 2, a
continuous web of the provisional optical film is fed to the lamination
line or provisional-optical-film feed line 530 by the lamination drive
mechanism 540. In Steps 3 and 4, the provisional carrier film 14' is
peeled and detached by the provisional-carrier-film take up drive
mechanism 576 of the provisional-carrier-film peeling unit 575, and then,
in Step 5, a defect or defects existing in the polarizing composite film
11 with the adhesive layer12 in an exposed state is detected by the
inspection unit 560.

[0207] The inspection unit 560 comprises an image-reading device 590
including for example a CCD camera. The image-reading device 590 is
electrically connected to the information processing device 610 included
in the control unit 610, whereby in the image data read by the
image-reading device 590 is processed in association with measurement
data measured by the distance measurement device 550 electrically
connected to the information processing device 610. The control unit 600
functions to operate the information processing device 610 and the
storage device 620 to process the image data from the image-reading
device 590 in association with the feed-length measurement data on the
fed-out distance measured in terms of the length from the leading edge of
the provisional optical film by the distance measurement device 550, so
as to create position data representing the locations or coordinate
positions of defects in the polarizing composite film 11 having the
adhesive layer12 in exposed state, and then store the position data in
the storage device 620. The control unit 600 is operable at first, based
on the position data on the detected defect locations or coordinate
positions, to define defective regions and normal regions in the
polarizing composite film 11. Further, the control unit 600 functions,
based on the defective and normal regions defined in the polarizing
composite film 11, to create slit-position information. The slit-position
information is information indicating the positions at which respective
ones of the slit lines are to be formed in the continuous web of optical
film (final optical film), and the slit lines are formed in pairs by the
slitting unit 150 during the manufacturing process of liquid-crystal
display elements, in a manner as to slit the continuous web of optical
film being fed in a direction transverse to the feed direction of the
continuous web, from the surface opposite to the carrier film to a depth
reaching the adhesive layer surface of the carrier film. The
slit-position information thus created is also stored in the storage
device 620. Then, the information processing device 610 functions, based
on the stored slit-position information, to create encoded information,
together with additional information, such as the manufacturing lot and
the length in meters of the web in the roll of the optical film, or in
association with the additional information. The manner of creating the
encoded information is common in the disclosed embodiments so that it
will be described later in connection with FIG. 18 and FIGS. 19 to 21.

[0208] In Steps 6 and 7, the carrier film 14 subjected to only a releasing
treatment is taken out by the carrier-film lamination mechanism 570 which
also serves as a film-feeding drive mechanism. In Step 8, the taken out
carrier film 14 is laminated to the exposed adhesive layer 12. The
information processing device 610 defines defective regions and normal
regions in the polarizing composite film 11, based on the locations or
coordinate positions of the defects detected in Step 5, and then, based
on the defined defective and normal regions, creates slit-position
information for forming defective polarizing sheets Xβ and normal
polarizing sheets Xα in the polarizing composite film 11. In Step
9, the created slit-position information is recorded on a surface of the
carrier film 14 laminated on the polarizing composite film 11, by the
information recording unit 630. Finally in Step 10, the optical film
formed through the above Steps is wound by the optical-film take up drive
mechanism 580 into a roll of the optical film laminate. The embodiment
illustrated in FIG. 13 is different from the embodiment illustrated in
FIG. 12 in that the roll of the provisional optical film laminate 10' is
first produced and prepared. Further, the embodiment in FIG. 13 is
different from the embodiment in FIG. 12 in that when the provisional
carrier film 14' having the transferable adhesive layer 12 provided
thereon is peeled, the polarizing composite film 11 is formed, on the
surface exposed by peeling, with the transferred adhesive layer 12, and
the inspection of defects existing in the polarizing composite film 11 is
conducted on the polarizing composite film having such exposed adhesive
layer 12.

[0209] Although not illustrated in FIG. 13 or 16, it may be possible,
particularly in the process of manufacturing roll of the provisional
optical film laminate, in advance of Step 10, to laminate a
surface-protection film 13 having an adhesive surface on the surface of
the polarizing composite film 11 opposite to the surface on which the
carrier film 14 is laminated by means of a separately provided
surface-protection-film lamination mechanism 640, before the protective
film is laminated to the polarizer, irrespective of whether the
protective film is subjected to a hard coat treatment or an anti-dazzling
or anti-glare treatment on one surface.

[0210] In this case, the resulting optical film has a structure having the
carrier film 14 and the surface-protection film 13 laminated to
respective ones of the opposite surfaces of the polarizing composite film
11.

(Method and System for Manufacturing Roll of Optical Film Laminate
According to the Embodiment Illustrated in FIG. 14)

[0211]FIG. 14 is a schematic diagram showing the optical-film
manufacturing system for a roll of an optical film laminate10, wherein a
roll of a provisional optical film laminate 10'' is mounted on a support
rack, the provisional optical film laminate comprising a polarizing
composite film 11 including a polarizer and a protective film laminated
thereon, and a provisional carrier film 14' releasably laminated on the
polarizing composite film 11 through an adhesive layer; and a provisional
surface-protection film 13' laminated on the surface of the polarizing
composite film 11 opposite to the surface on which the provisional
carrier film 14' is laminated, and wherein the provisional carrier film
14' and the provisional surface-protection film 13' are continuously
peeled from the continuous web of the provisional optical film being
continuously unrolled from the roll to have the adhesive layer exposed
and the optical film having the exposed adhesive layer is subjected to an
inspection for the existence of defects in the polarizing composite film
11, a carrier film 14 being then releasably laminated on the adhesive
layer 12 of the polarizing composite film 11, and a surface-protection
film 13 being releasably laminated through the adhesive surface on the
surface of the polarizing composite film opposite to the surface on which
the carrier film 14 is not laminated, in a sequential manner;
slit-position information being thereafter recorded on a surface of the
carrier film 14 in the same manner as in the embodiments in FIGS. 13 &
14. FIG. 17 is a flowchart showing the manufacturing process or steps in
the system.

[0212] It is to be repeated that, in the process of producing the roll of
the provisional optical film laminate 10'', a transferable adhesive layer
is first provided on the provisional carrier film 14'. Thus, when the
provisional carrier film 14' is peeled from the continuous web of the
provisional optical film being continuously fed out from the roll, the
adhesive layer 12 formed on the provisional carrier film is transferred
to the polarizing composite film 11 so as to be incorporated into the
polarizing composite film 11. In place of the provisional carrier film
14' formed with the transferable adhesive layer, an adhesive layer 12 may
first be provided on the polarizing composite film, and then a
provisional carrier film 14'' may be laminated on the adhesive layer 12
after being subjected to a releasing treatment. Further, as the
protective film to be attached to the polarizer, it may be possible to
use a film which is subjected to a hard coat treatment or an
anti-dazzling or anti-glare treatment at the surface to which the
surface-protection film is attached. The provisional surface-protective
film 13' and the surface-protective film 13 are formed with
non-transferable adhesive surfaces at the sides which are to be laminated
on the polarizing composite film 11. Typically, the surface-protection
film 13 is formed as a sheet integral with the normal polarizing sheet to
be laminated to a liquid-crystal panel, thus the surface-protection film
sheet 13 having the adhesive surface is used as means to protect the
surface of an associated liquid-crystal display element during the
liquid-crystal display element manufacturing process, and, after
completion of the manufacturing process, it is peeled and removed
together with the adhesive surface.

[0213] The manufacturing system 500 for a roll of the optical film
laminate 10 according to the embodiment illustrated in FIG. 14 comprises
a a lamination line or provisional-optical-film feed line 530 including a
support rack 531 having a roll of the provisional optical film laminate
10'' rotatably mounted thereon as in the embodiment illustrated in FIG.
13, and the feed line 530 includes a lamination drive mechanism 540
including a pair of feeding drive rollers for continuously feeding the
provisional optical film. The lamination drive mechanism 540 comprises a
length or distance measurement device 550 having an encoder incorporated
in one of the feeding drive rollers to calculate the fed-out distance in
terms of a length from the leading edge of the provisional optical film.
The manufacturing system 500 further comprises a provisional-carrier-film
peeling unit 575 including a provisional-carrier-film take up drive
mechanism 576. The manufacturing system 500 also comprises the following
elements as in the system according to the embodiment illustrated in FIG.
12; an inspection unit 560 including an image-reading device 590 for
inspecting existence of defects in the polarizing composite film 11; a
carrier-film lamination mechanism 570 comprising a support rack 571
having a roll of the carrier film 14 rotatably mounted thereon; an
optical-film take up drive mechanism 580 for drivingly winding the
produced optical film into a roll; a control unit 600 including an
information processing device 610 for performing information processing
and a storage device 620 for storing therein processed information; and
the information recording unit 630 for recording encoded information on
the optical film. Additionally, the manufacturing system 500 comprises a
provisional surface-protection-film peeling unit 645 including a
provisional surface-protection-film take up drive mechanism 646 for
taking up and peeling the provisional surface-protection film 13', and a
surface-protection film lamination mechanism 640 for attaching the final
surface-protection film 13 to the polarizing composite film at the
surface opposite to the surface on which the final carrier film 14 is
laminated, the surface-protection film lamination mechanism 640 also
serving as a film-feeding drive mechanism.

[0214] Referring to the respective ones of the manufacturing steps
illustrated in FIG. 17, in Step 1, the roll of the provisional optical
film laminate 10'' is mounted on the support rack 531. The provisional
optical film comprises a polarizing composite film 11 including a
polarizer having a protective film laminated to one or each of the
opposite surfaces of the polarizer, and a provisional carrier film 14'
formed with a transferable adhesive layer and laminated on the polarizing
composite film 11. In Step 2, a continuous web of the provisional optical
film is fed by the lamination drive mechanism 540. In Steps 3 and 4, the
provisional carrier film 14' is peeled and detached by the
provisional-carrier-film take up drive mechanism 576 of the
provisional-carrier-film peeling unit 575. Next, in Steps 5 and 6, the
provisional surface-protection film 13' which is laminated through an
adhesive surface on the polarizing composite film at the surface on which
the provisional carrier film 14' is laminated, is peeled and detached by
the provisional surface-protection-film take up drive mechanism 646 of
the provisional surface-protection-film peeling unit 645. In Step 7, an
inspection is conducted by the inspection unit 560 on the polarizing
composite film 11 having the adhesive layer in an exposed state, for
existence of defects therein.

[0215] The inspection unit 560 comprises an image-reading device 590
including for example a CCD camera. The image-reading device 590 is
electrically connected to the information processing device 610 included
in the control unit 610, wherein image data read by the image-reading
device 590 is processed in association with feed-length measurement data
measured by the length or distance measurement device 550 electrically
connected to the information processing device 610. The control unit 600
is operable to cause the information processing device 610 and the
storage device 620 to process the image data from the image-reading
device 590 in association with the feed-length measurement data relating
to the fed-out distance measured in terms of a length from the leading
edge of the provisional optical film by the length or distance
measurement device 550, so as to create position data representing
locations or coordinate positions of defects in the polarizing composite
film 11 which has the adhesive layer 12 in the exposed state, and then
store the position data in the storage device 620. Then, the control unit
600 functions, based on the position data relating to the detected
locations or coordinate positions of defects, to define defective regions
and normal regions in the polarizing composite film 11. Further, the
control unit 600 functions, based on the defective and normal regions of
the polarizing composite film 11 thus defined, to create slit-position
information. The slit-position information is the one which indicates the
positions at which respective ones of the slit lines are to be formed in
the continuous web of optical film, and the slit lines are formed in
pairs by the slitting unit 150 during the manufacturing process of
liquid-crystal display elements, in a manner as to slit the continuous
web of optical film being fed in a direction transverse to the feed
direction of the continuous web, from the surface opposite to the carrier
film to a depth reaching the adhesive layer surface of the carrier film.
The created slit-position information is also stored in the storage
device 620. Then, the information processing device 610 functions, based
on the stored slit-position information, to create encoded information,
together with additional information, such as the manufacturing lot and
the length in meters of the optical film in the roll, or in association
with the additional information. The manner of creating the encoded
information is identical with those in the disclosed embodiments, so that
it will be described later in connection with FIG. 18 and FIGS. 19 to 21.

[0216] In Steps 8 and 9, the carrier-film lamination mechanism 570 which
also serves as a film-feeding drive mechanism feeds the carrier film 14
which has been subjected only to a releasing treatment. In Step 10, the
delivered carrier film 14 is laminated on the exposed adhesive layer 12
in a releasable manner. Further, in Steps 11 and 12, the
surface-protection film 13 having the adhesive surface is fed out by the
surface-protection film lamination mechanism 640 which also serves as the
film-feeding drive mechanism. In Step 13, the adhesive surface of the fed
final surface-protection film 13 is laminated through the adhesive
surface on the surface of the polarizing composite film opposite to the
surface on which the carrier film 14 will not be laminated. This is the
Step 13.

[0217] Then, the information processing device 610 functions to define
defective regions and normal regions in the polarizing composite film 11,
based on locations or coordinate positions of the defects detected in
Step 7, and then, based on the defined defective and normal regions,
creates slit-position information for forming defective polarizing sheets
Xβ and normal polarizing sheets Xα in the polarizing composite
film 11. In Step 14, the created slit-position information is recorded on
a surface of the carrier film 14 laminated on the polarizing composite
film 11, by the information recording unit 630. Finally, in Step 15, the
optical film formed through the above Steps is wound by the optical-film
take up drive mechanism 580, to form a roll of the optical film laminate.

[0218] The embodiment in FIG. 14 is different from the embodiment in FIG.
13, in that the roll of the provisional optical film laminate 10'' is
first prepared with a structure wherein not only the provisional carrier
film 14' but also the provisional surface protection film 13' are
laminated on the polarizing composite film 11. Therefore, in the
embodiment in FIG. 14, the inspection of defects is carried out with
respect to the polarizing composite film including the adhesive layer 12
exposed by sequentially peeling the provisional carrier film 14' and the
provisional surface-protection film 13'.

[0219] In the embodiment illustrated in FIG. 12, the optical-film take up
drive mechanism 580 is configured to operate in an inter-related manner
with the operation of at least the lamination drive mechanism 540, the
inspection unit 560 and the carrier-film lamination mechanism 570, to
take up the optical film having the encoded information 20 recorded on a
surface of the carrier film 14. In the embodiments illustrated in FIGS.
13 & 14, the optical-film take up drive mechanism 580 is configured to
operate in an inter-related manner with at least the lamination drive
mechanism 540, the take up drive mechanism (576, 646), the carrier-film
lamination mechanism 570 and the surface-protection film lamination
mechanism 640, to take up the optical film having the encoded information
20 recorded on a surface of the carrier film 14. The manufacturing
systems 500 may be provided with a speed adjustment mechanism (not shown)
including a feed roller in order to adjust the take up speed of the
optical film, when needed. Further, the encoded information may be
recorded on the surface-protection film 13, instead of the carrier film
14.

(Creation of Encoded Information)

[0220] An embodiment of creating the encoded information 20 including
information relating to the positions of the defects in the above
embodiments is shown in the tables and schematic diagrams of FIGS. 22 to
25. It is to be understood that the encoded information 20 may be
recorded in a variety of ways including, for example a mode in which
encoded information is entirely recorded on a single storage medium, and
a mode in which encoded information is recorded on a plurality of storage
media disposed at given intervals (e.g., at intervals of 1 m or 100 m).
The selection of the recording modes or the content of position
information to be stored as the encoded information may be determined
depending on the function required for the liquid-crystal display element
manufacturing method and system.

[0221] Thus, it should be noted that the embodiments illustrated in the
schematic diagram and the flowcharts of FIG. 18 and FIGS. 19 to 21 are
shown only by way of examples.

[0222] The encoded information 20 comprises encoded information recorded
on the continuous web unrolled from the roll of the optical film laminate
10 and is comprised of information for identifying the previously defined
defective and normal regions in the polarizing composite film 11
including an adhesive layer 12, and slit-position information for forming
defective polarizing sheets and normal polarizing sheets corresponding to
the defective and normal regions, together with or in association with
additional information, such as the manufacturing lot and the length in
meters of the web in the roll. The encoded information 20 may be any type
of code, as long as it is readable by the reading unit 120 of the
liquid-crystal display element continuous manufacturing system 1 during
the liquid-crystal display element manufacturing process.

[0223] FIG. 18 is a schematic diagram showing the manner of calculating
the positions at which respective ones of the slit lines are to be formed
for delimiting the defective and normal regions in the continuous web of
optical film which is being transported.

[0224] The control unit 600 functions to operate the information
processing device 610 and the storage device 620 to process image data
from the image-reading device 590 in association with feed-length
measurement data relating to the length fed from the leading edge of the
polarizing composite film 11 by the length or distance measurement device
550, so as to create position data representing the locations or
coordinate positions of defects existing in the polarizing composite
film, and then store the position data in the storage device 620. Then,
the control unit 600 functions to define defective regions and normal
regions in the polarizing composite film 11, based on the position data
relating to the detected locations or coordinate positions of defects.
Further, the control unit 600 functions to create slit-position
information, based on the defective and normal regions of the polarizing
composite film 11. The slit-position information is the one which
indicates the positions at which respective ones of the slit lines are to
be formed in the continuous web of optical film, and the slit lines are
formed in pairs by the slitting unit 150 during the manufacturing process
of liquid-crystal display element, in a manner as to slit the continuous
web of optical film being fed in a direction transverse to the feed
direction of the continuous web, from the surface opposite to the carrier
film to a depth reaching the adhesive layer surface of the carrier film.
The created slit-position information is also stored in the storage
device 620. Then, the information processing device 610 operates to
create encoded information based on the stored slit-position information,
together with additional information, such as the manufacturing lot and
the length in meters of the web in the roll of the optical film laminate,
or in association with additional information. FIGS. 19 to 21 are
flowcharts showing three different processes for calculating the
positions at which the respective ones of the slit lines are to be formed
in the continuous web of optical film being fed.

[0225] The calculation processes will be described below based on the
schematic diagram and the flowcharts of FIGS. 19 to 21. The schematic
diagram of FIG. 18 shows the polarizing sheet 11' consisting of a
polarizer having a protective film laminated thereon, or the polarizing
composite film 11 having an adhesive layer (both of the polarizing sheet
11' and the polarizing composite film 11 will hereinafter be referred to
collectively as "polarizing composite film 11") being continuously fed in
right direction by the feed roller of the carrier-film lamination
mechanism 570. However, in view of the fact that the optical film is
formed by the carrier-film lamination mechanism 570 by laminating the
carrier film 14 formed with a transferable adhesive layer thereon is
releasably laminated on the polarizing sheet 11' consisting of the
polarizer having the protective film laminated thereon, the polarizing
composite film being continuously supplied by the feed roller will herein
be referred to generically as the "optical film". The flowcharts of FIGS.
19 to 21 show a specific steps up to the time when the encoded
information 20 created by the control unit 600 is recorded on the optical
film, preferably, on the surface of the carrier film 14, and the optical
film having the encoded information recorded thereon is taken up by the
optical-film take up drive mechanism 580.

[0226] In either case, in Step 1, the control unit 600 operates to
instruct the lamination drive mechanism 540 and the optical-film take up
drive mechanism 580 to feed the optical film. In Step 2, the control unit
600 instructs the inspection unit 560 including the image-reading device
590 to detect the locations or coordinate positions of defects existing
in the optical film, and store the detected locations or coordinate
positions of the defects together with the type and size of the detected
defects. In Steps 3 and 4, the control unit 600 functions to determine
the relationship between the length of a sheet of the optical film and
the length (Xα) corresponding to that of a normal region. The
method of determining the relationship is as follows.

[0227] In Step 3, the control unit 600 functions to operate the
information processing device 610 to calculate the distance X between a
reference position of the optical film being fed and the location of the
defect, and store the calculated distance X in the storage device 620. As
shown in FIG. 18, the distance X is a distance for example between the
position of the carrier-film lamination mechanism 570 (the reference
position of the optical film) and the position of the inspection unit 560
(or the image-reading device 590) (the defect position).

[0228] In Step 4, the control unit 600 further functions to operate the
information processing device 610 to subtract the length (Xα)
corresponding to that of the normal region from the distance X to obtain
a distance (X-Xα)=X', and then store the distance X' in the storage
device 620. The length (Xα) corresponding to that of the normal
region of the optical film is determined by a system manager based on the
size of the liquid-crystal panel and pre-stored in the storage device
620. Then, the control unit 600 functions to operate the information
processing device 610 to determine whether the calculated distance X' is
greater or less than the length (Xα) corresponding to that of the
normal region of the optical film.

[0229] Specifically, if the relation X' (or X'') in FIG. 18>Xα is
established, it is understood that the normal region (Xα) of the
optical film can be ensured, so that the control unit 600 instructs the
lamination drive mechanism 540 and the optical-film take up drive
mechanism 580 to have the optical film delivered under tension by the
length (Xα) of the normal region. The value of the length
(Xα) in this instance is the slit-position information for forming
a normal polarizing sheet Xα corresponding to the normal region in
the optical film.

[0230] To the contrary, if the relation is X'≦Xα, i.e., X'''
in FIG. 18≦Xα, it is understood that the normal region
(Xα) of the optical film cannot be ensured. In this instance, the
region of the optical film having the length (Xβ) provides the
defective polarizing sheet (Xβ), so that the control unit 600
functions to operate the information processing device 610 to calculate
the length (X'+X0)=Xβ corresponding to the defective region
(Xβ) by adding a constant value X0 to X' (X''' in FIG. 18), and to
instruct the lamination drive mechanism 540 and the optical-film take up
drive mechanism 580 to feed the optical film under tension by the length
(Xβ) of the defective region. The value (Xβ) in this instance
is the slit-position information for forming a defective polarizing sheet
Xβ corresponding to the defective region of the optical film.

[0231] Specifically, the control unit 600 operates to calculate the
following (a) and (b) to create slit-position information indicative of
the positions at which respective ones of the slit lines are to be formed
in a continuous web of optical film to be fed during the manufacturing
process of liquid-crystal display elements to form normal polarizing
sheets Xα and defective polarizing sheets Xβ of a polarizing
composite film, and then store the slit-position information in the
storage device 620:

[0232] (a) a distance (Xα) to the position for forming a next slit
line, if X'>Xα; and

[0233] (b) a distance (X'+X0=Xβ) to the position for forming a next
slit line, if X'≦Xα.

[0234] By the way, if the length (X'+X0=Xβ) corresponding to that of
the defective region becomes equal to the length (Xα) corresponding
to that of the normal region, i.e., if (X'+X0)=(Xα), the control
unit 600 cannot identify or discriminate the normal region (Xα)
over the defective region (Xβ). This means that the region to be
recognized as the defective region (Xβ) may not be recognized as the
defective region (Xβ), so that, for example, the normal region
(Xα) and the defective region (Xβ) cannot be discriminated
from each other based on feed-length measurement data on the feed length
of the optical film, and the encoded information created based on the
feed-length measurement data (X'+X0) inevitably becomes imperfect. It is
assumed that such a situation occurs when the location or coordinate
position of a defect in the optical film is infinitely close to the
position for forming a next slit line in the optical film, or when a
series of defects are distributed over a length (Xα) corresponding
to that of the normal region.

[0235] In Step 5, if (X'+X0) becomes equal to (Xα), the control unit
600 functions to operate the information processing device 610 to perform
a calculation based on at least one of the following methods to create
information for identifying or discriminating the normal region
(Xα) over the defective region (Xβ).

[0236] In Step 5 illustrated in FIG. 19, even if, as the result of
calculation conducted by the information processing device 610, the
distance (X'+X0) to the position for forming a next slit line becomes
equal to the length (Xα) corresponding to that of the normal
region, the region in said distance is not essentially the normal region
(Xα). In order to make it possible to recognize such difference,
for example, as defect-including information Xγ illustrated in FIG.
23, a numerical suffix "0" may be associated with the slit-position
information indicating the position for forming a slit-line corresponding
to the normal region, and a numerical suffix "1" with the slit-position
information indicating the position for forming a-slit-line corresponding
to the defective region. In Step 5 illustrated in FIG. 20, if, as a
result of calculation of the information processing device 610, the
distance (X'+X0) to the position where a next-slit-line is to be formed
becomes equal to the length (Xα) corresponding to that of the
normal region, an information processing is conducted so that the
distance to the position where a next-slit-line is to be formed satisfies
the relation (X'+X0'), wherein X0'>X0, and store the distance (X'+X0')
in the storage device 620. As shown in FIG. 24, this information
processing makes it possible by calculating the distance (X'+X0')
different from Xα, to allow the region having the length (X'+X0')
to be identified or discriminated over the normal region (Xα).
Further, in Step 5 illustrated in FIG. 21, if, as the result of
calculation conducted by the information processing device 610, the
distance (X'+X0) to the position where a next-slit-line is to be formed
becomes equal to the length (Xα) corresponding to that of the
normal region, an information processing is carried out to allow the
distance to the position where the next-slit-line is to be formed to
become [(X'+X0)/m], wherein m=2 or more, preferably 2 or 3, and store the
distance [(X'+X0)/m] in the storage device 620. As in the case of FIG.
20, this information processing illustrated in FIG. 25 is also configured
to calculate the [(X'+X0)/m] different from Xα to allow the region
having the length [(X'+X0)/m] to be identified or discriminated over the
normal region (Xα).

[0237] Summarizing the above, in the process for creating information for
identifying or discriminating the defective and normal regions, either of
the following methods may be adopted:

[0238] (1) A method of creating defect-including information Xγ as
information for identifying or discriminating a region having a length
(X'+X0) calculated by the information processing device 610 over the
normal region (Xα);

[0239] (2) A method of creating a distance to the position where a
next-slit-line is to be formed which is calculated by the information
processing device 610, as a distance (X'+X0') (wherein X0'>X0) which
is different from Xα; and

[0240] (3) A method of creating a distance to the position where a
next-slit-line is to be formed which is calculated by the information
processing device 610, as a distance [(X'+X0)/m] (wherein m=2 or more)
which is different from Xα.

[0241] Particularly, in cases where the method (2) or (3) is employed,
(X'+X0)=(Xα) is changed to (X'+X0')≠Xα or
[(X'+X0)/m]≠Xα through the information processing illustrated
in FIG. 20 or 21, thus the position where a next-slit-line is to be
formed can be used as information indicating the defective region
identified or discriminated over the normal region.

[0242] Next, in either case, in Step 6, the control unit 600 functions to
operate the information processing device 610 to determine the length
between the reference position and the position where a next-slit-line is
to be formed, based on the calculation result in Steps 4 and 5. In the
methods (2) or (3), in Step 7, the control unit 600 operates to cause the
information processing device 610 to store the length to the position
where a next-slit-line is to be formed as determined in Step 6, in the
storage device 620. However, in the case of the method (1), the control
unit 600 functions to operate the information processing device 610 to
store the length to the position of forming a next-slit-line in
association with the defect-including information Xγ, in the
storage device 620.

[0243] In either case, in Step 8, the control unit 600 functions to
operate the information processing device 610 to convert, based on the
position for forming a next-slit-line stored in Step 7, into encoded
information, the slit-position information indicating the position where
a slit-line is to be formed with respect to the leading edge of the
optical film being fed, together with or in association with additional
information, such as the manufacturing lot and the length in meters of
the optical-film in the roll. In the method (1), it is to be understood
that the defect-including information Xγ is simultaneously
converted to the encoded information.

[0244] In Step 9, the control unit 600 functions to operate the
information recording unit 630 to record the encoded information
converted in Step 8 by the information processing device 610, on the
optical film, preferably on the surface of the carrier film. In the
method (1), it should be understood that the encoded defect-including
information Xγ is also recorded together with the encoded
information. Finally, in Step 10, the control unit 600 functions to
operate the lamination drive mechanism 540 and the optical-film take up
drive mechanism 580 to wind the finished optical film. The roll of the
optical film laminate is thus completed. Then, examples of the encoded
information are shown in FIGS. 22 to 25.

(Details of the Manufacturing System for a Roll of Optical Film Laminate
Specifically Showing Defect Inspection Process)

[0245] With reference to FIGS. 26 and 27, the manufacturing system for a
roll of the optical film laminate will be more specifically described in
connection with a specific method of inspecting defects existing in the
polarizing composite film 11. FIG. 26 is a schematic diagram showing a
manufacturing system of a roll of the optical film laminate 700 having
two inspection units, which is based on the manufacturing system
according to the embodiment illustrated in FIG. 13.

[0246] In the manufacturing process of the roll of provisional optical
film 10', a polarizing sheet 11' is formed with a structure comprising a
polarizer having a protective film laminated on at least one of the
opposite surfaces of the polarizer, and an adhesive layer 12 is formed on
the other surface of the polarizing sheet 11' to form a polarizing
composite film 11. Then, a provisional carrier film 14' is releasably
laminated on the adhesive layer 12 of the polarizing composite film 11,
and the resulting provisional optical film is wound into a roll to form
the roll of the provisional optical film laminate 10'. The roll of the
provisional optical film laminate 10' is rotatably mounted on a support
rack 711 of a provisional-optical-film feed unit 710. In addition to the
provisional-optical-film feed unit 710, the manufacturing system 700
comprises a provisional-carrier-film take up drive mechanism 720, a first
inspection unit 730, a second inspection unit 731, a control unit 740, a
carrier-film feed unit 750, a carrier-film lamination mechanism 760, an
optical-film take up drive mechanism 770, and an information recording
unit 780.

[0247] The provisional optical film is continuously delivered from the
roll of the provisional optical film laminate 10' by the
provisional-optical-film feed unit 710. The provisional-carrier-film take
up drive mechanism 720 is disposed along the feed direction of the
provisional optical film, and adapted to take up the provisional carrier
film 14' by peeling and detaching it from the provisional optical film.
Each of the first and second inspection units 730, 731 is adapted to
detect one or more defects in the surface and the interior of the
polarizing composite film 11 with the adhesive layer12 exposed as a
result of the peeling the provisional carrier film 14'. The first
inspection unit 730 is comprised of a transmission inspection device
illustrated in FIG. 28. The transmission inspection method is designed
such that a visible light emitted from a light source is projected
perpendicularly to the polarizing composite film 11, the light which has
passed through the polarizing composite film 11 being received by an
optical detection unit to detect one or more defects existing in the
polarizing composite film 11 in the form of a shade. The second
inspection unit 731 is comprised of a cross-Nicol transmission inspection
device illustrated in FIG. 28. The cross-Nicol transmission inspection
method is designed such that a visible light from a light source is
introduced perpendicularly or obliquely into the polarizing film 11
associated with a polarization filter which is disposed immediately
before an optical detection unit in such a manner that the absorption
axis of the polarization filter is oriented at a right angle with respect
to the absorption axis of the polarizing composite film11, the light
which has passed through the polarizing composite film 11 being received
by the optical detection unit to detect one or more defects existing in
the polarizing composite film11 as a bright spot.

[0248] The control unit 740 functions to define defective regions and
normal regions in the polarizing composite film 11, based on locations or
coordinate positions of one or more defects detected by the first
inspection unit 730 and the second inspection unit. Then, the control
unit 740 functions to operate an information processing device 741 to
create slit-position information for forming defective polarizing sheets
Xβ and normal polarizing sheets Xα in the polarizer film,
based on the defined defective and normal regions, and convert the
slit-position information into encoded information 20. The information
recording unit 780 is adapted to record the encoded information on a
surface of the carrier film 14 newly laminated on the polarizing
composite film 11.

[0249] The carrier-film feed unit 750 disposed downstream of the second
inspection unit 731 is adapted to continuously unroll the carrier film 14
from a roll of the carrier film14 rotatably mounted in the support rack
751, along the feed direction of the polarizer film 11. The carrier-film
lamination mechanism 760 is provided with a pair of rollers, and adapted
to releasably laminate the carrier film 14 on the exposed adhesive layer
12 after completion of the inspection by the inspection units. It may be
repeated that, the encoded information is recorded on the surface of the
carrier film 14 newly laminated on the adhesive layer, by the information
recording unit 780. The created optical film is wound by the optical-film
take up drive mechanism 770, and formed into a roll of the optical film
laminate 10. The control unit 740 functions to control respective
operations of the units, the mechanisms and the devices in an
inter-related manner.

[0250]FIG. 27 is a schematic diagram showing a manufacturing system of
the roll of the optical film laminate 800 having four inspection units,
which is based on the manufacturing system according to the embodiment in
FIG. 14.

[0251] In the manufacturing process of the provisional optical film 10'',
a polarizing sheet 11' is produced as comprising a polarizer having a
protective film laminated on at least one of the opposite surfaces of the
polarizer, and an adhesive layer 12 is formed on the other surface of the
polarizing sheet 11' to form a polarizing composite film 11. Then, a
provisional carrier film 14' is releasably laminated on the adhesive
layer 12 of the polarizing composite film 11, and a provisional
surface-protection film 13' is releasably laminated on the surface of the
polarizing composite film 11 opposite to the surface on which the
provisional surface-protection film 14' is laminated, the resulting
provisional optical film is wound into a roll of the provisional optical
film laminate 10'' The roll of provisional optical film laminate 10'' is
rotatably mounted in a support rack 811 of a provisional-optical-film
feed unit 810.

[0252] In addition to the provisional-optical-film feed unit 810, the
system 800 comprises a provisional-carrier-film take up drive mechanism
820, a provisional-surface-protection-film take up drive mechanism 830, a
first inspection unit 840, a second inspection unit 850, a third
inspection unit 851, a fourth inspection unit 852, a control unit 860, a
provisional-surface-protection-film feed unit 870, a carrier-film feed
unit 880, two sets of lamination mechanisms 890 (a carrier-film
lamination mechanism 891, a surface-protection-film lamination mechanism
892), an optical-film take up drive mechanism 910, and an information
recording unit 920.

[0253] The provisional optical film10' is continuously unrolled from the
roll of the provisional optical film laminate 10'' by the
provisional-optical-film feed unit 810. The
provisional-surface-protection-film take up drive mechanism 830 is
disposed along the feed direction of the provisional optical film, and
adapted to take up the provisional surface-protection film 13' by peeling
and detaching it from the provisional optical film. The
provisional-carrier-film take up drive mechanism 820 is disposed
downstream of the provisional-surface-protection-film take up drive
mechanism 830 and along the feed direction of the provisional optical
film, and adapted to take up the provisional carrier film 14' by peeling
and detaching it from the provisional optical film.

[0254] As shown in FIG. 27, the inspection units are disposed at
respective four positions in the system 800. The first inspection unit
840 is located between the provisional-surface-protection-film take up
drive mechanism 830 and the provisional-carrier-film take up drive
mechanism 820, and adapted to inspect the provisional optical film in a
state where only the provisional surface-protection film 13' is peeled
and the provisional carrier film 14' is still on the web. Specifically,
the inspection is made to detect one or more defects in the surface of
the polarizing composite film 11, based on the reflected light from the
protective film of the exposed polarizing composite film 11. The second
inspection unit 850, the third inspection unit 851 and the fourth
inspection unit 852 are located between the provisional-carrier-film take
up drive mechanism 820 and the carrier-film feed unit 880, so that they
inspect one or more defects on the surface and the interior of the
polarizing composite film by having light transmit through the polarizing
composite film 11 having the adhesive layer 12 in exposed state as a
result of the peeling the provisional carrier film 13' by the
provisional-carrier-film take up drive mechanism 820.

[0255] More specifically, each of the second to fourth inspection units is
configured as follows. The second inspection unit 850 is designed for the
transmission inspection illustrated in FIG. 28. The transmission
inspection method is designed such that a visible light from a light
source is projected perpendicularly to the polarizing composite film 11,
the light which has passed through the polarizing composite film 11 being
received by an optical detection unit to detect one or more defects
existing in the polarizing composite film 11 in the form of a shade. The
third inspection unit 851 is designed for the oblique transmission
inspection illustrated in FIG. 28. The oblique transmission inspection
method is designed such that a visible light emitted from an
oblique-transmission light source is projected to the polarizing
composite film 11 in an oblique angle, the light which has passed through
the polarizing composite film being received by an optical detection unit
to detect one or more defects existing in the optical film as a shade.
The fourth inspection unit 852 is comprised of a cross-Nicol transmission
inspection device illustrated in FIG. 28. The cross-Nicol transmission
inspection method is designed such that a visible light from a light
source is introduced perpendicularly or obliquely into the polarizing
film 11 associated with a polarization filter which is disposed
immediately before an optical detection unit in such a manner that the
absorption axis of the polarization filter is oriented at a right angle
with respect to the absorption axis of the polarizing composite film11,
the light which has passed through the polarizing composite film 11 being
received by the optical detection unit to detect one or more defects
existing in the polarizing composite film11 as a bright spot.

[0256] The control unit 860 functions to define in the polarizing
composite film 11 defective regions and normal regions, based on
locations or coordinate positions of one or more defects detected by the
first inspection unit 840, the second inspection unit 850, the third
inspection unit 851 and the fourth inspection unit 852. Then, the control
unit 860 functions to operate an information processing device 861 to
create slit-position information for forming defective polarizing sheets
Xβ and normal polarizing sheets Xα in the polarizer composite
film, based on the defined defective and normal regions, and convert the
slit-position information into encoded information 20. The information
recording unit 920 is adapted to record the encoded information on a
surface of the carrier film 14 newly laminated to the polarizing
composite film 11.

[0257] The carrier-film feed unit 880 disposed downstream of the fourth
inspection unit 852 is adapted to continuously unroll the carrier film 14
from the roll of the carrier film laminate 14 rotatably mounted in a
support rack 881, along the feed direction of the polarizer film 11. The
surface-protection-film feed unit 870 disposed downstream of the
carrier-film feed unit 880 is adapted to continuously unroll the
surface-protection film 13 from a roll of the surface-protection film 13
rotatably mounted in a support rack 871, along the feed direction of the
polarizer film 11. The lamination mechanisms 890, or the carrier-film
lamination mechanism 891 and the surface-protection-film lamination
mechanism 892 each having a pair of rollers function to releasably
laminate the carrier film 14 and the surface-protection film 13
respectively on the exposed adhesive layer 12 and the surface of the
polarizing composite film which does not have an adhesive layer, after
completion of the inspection by the inspection units disposed at the four
positions. It may be repeated that, the encoded information is recorded
on the surface of the carrier film 14 newly laminated on the adhesive
layer, by the information recording unit 920. The created optical film is
wound by the optical-film take up drive mechanism 910, and formed into a
roll of the optical film laminate 10. The control unit 860 is operable to
control respective operations of the units, the mechanisms and devices in
an inter-related manner.

[0258] Although the present disclosure has been described in connection
with disclosed embodiments thereof, it will be appreciated that various
changes and modifications will be made by those skilled in the art
without departing from the spirit and scope of the invention, defined in
the following claims, and legal equivalents of the following claims may
be substituted for elements thereof. Accordingly, the present disclosure
is not limited to the specific embodiments disclosed as the best mode for
carrying out the disclosure, but intended to cover all embodiments
included within the scope thereof.